NETVIRT-1037: Upstream Fixes --- Review-3
[netvirt.git] / vpnservice / vpnmanager / vpnmanager-impl / src / main / java / org / opendaylight / netvirt / vpnmanager / VpnUtil.java
index cb379e6541f2b0329fc2ce461eb6a86994d21a3b..8b1f05e101ea0f91e46dc4890a4b86d275b57c87 100755 (executable)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Ericsson India Global Services Pvt Ltd. and others. All rights reserved.
+ * Copyright © 2016, 2017 Ericsson India Global Services Pvt Ltd. and others. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
@@ -8,42 +8,60 @@
 
 package org.opendaylight.netvirt.vpnmanager;
 
+import com.google.common.base.Optional;
+import com.google.common.collect.Iterators;
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.MoreExecutors;
 import java.math.BigInteger;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
-import java.util.LinkedList;
+import java.util.Date;
+import java.util.HashSet;
 import java.util.List;
-import java.util.Objects;
+import java.util.Locale;
+import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
-
-import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
-import com.google.common.primitives.Ints;
-import com.google.common.util.concurrent.CheckedFuture;
-import com.google.common.util.concurrent.FutureCallback;
-import com.google.common.util.concurrent.Futures;
-
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
 import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;
 import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
-import org.opendaylight.genius.mdsalutil.MDSALUtil;
-import org.opendaylight.genius.mdsalutil.NwConstants;
-import org.opendaylight.netvirt.fibmanager.api.RouteOrigin;
 import org.opendaylight.genius.mdsalutil.FlowEntity;
+import org.opendaylight.genius.mdsalutil.FlowEntityBuilder;
 import org.opendaylight.genius.mdsalutil.InstructionInfo;
-import org.opendaylight.genius.mdsalutil.InstructionType;
-import org.opendaylight.genius.mdsalutil.MatchFieldType;
+import org.opendaylight.genius.mdsalutil.MDSALUtil;
 import org.opendaylight.genius.mdsalutil.MatchInfo;
 import org.opendaylight.genius.mdsalutil.MetaDataUtil;
+import org.opendaylight.genius.mdsalutil.NWUtil;
+import org.opendaylight.genius.mdsalutil.NwConstants;
+import org.opendaylight.genius.mdsalutil.actions.ActionRegLoad;
+import org.opendaylight.genius.mdsalutil.instructions.InstructionGotoTable;
+import org.opendaylight.genius.mdsalutil.instructions.InstructionWriteMetadata;
 import org.opendaylight.genius.mdsalutil.interfaces.IMdsalApiManager;
+import org.opendaylight.genius.mdsalutil.matches.MatchEthernetDestination;
+import org.opendaylight.genius.mdsalutil.matches.MatchMetadata;
+import org.opendaylight.genius.utils.ServiceIndex;
 import org.opendaylight.genius.utils.cache.DataStoreCache;
-import org.opendaylight.netvirt.neutronvpn.api.utils.NeutronConstants;
+import org.opendaylight.infrautils.jobcoordinator.JobCoordinator;
+import org.opendaylight.netvirt.bgpmanager.api.IBgpManager;
+import org.opendaylight.netvirt.fibmanager.api.FibHelper;
+import org.opendaylight.netvirt.fibmanager.api.RouteOrigin;
+import org.opendaylight.netvirt.neutronvpn.api.enums.IpVersionChoice;
 import org.opendaylight.netvirt.neutronvpn.interfaces.INeutronVpnManager;
-import org.opendaylight.netvirt.vpnmanager.utilities.InterfaceUtils;
+import org.opendaylight.netvirt.vpnmanager.api.InterfaceUtils;
+import org.opendaylight.netvirt.vpnmanager.api.VpnExtraRouteHelper;
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.VpnAfConfig;
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.VpnInstances;
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.VpnInterfaces;
@@ -51,179 +69,218 @@ import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev14081
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.instances.VpnInstanceKey;
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.VpnInterface;
 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.VpnInterfaceKey;
-import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.VpnInterfaceBuilder;
+import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.vpn._interface.VpnInstanceNames;
+import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.vpn._interface.VpnInstanceNames.AssociatedSubnetType;
+import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.vpn._interface.VpnInstanceNamesBuilder;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.Interfaces;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.Interface;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.interfaces.InterfaceKey;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.MacAddress;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.PhysAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.Uuid;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.Action;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.Instruction;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdManagerService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdPools;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPool;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPoolKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406.IfIndexesInterfaceMap;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406._if.indexes._interface.map.IfIndexInterface;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406._if.indexes._interface.map.IfIndexInterfaceKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.GetInterfaceFromIfIndexInput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.GetInterfaceFromIfIndexInputBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.GetInterfaceFromIfIndexOutput;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.OdlInterfaceRpcService;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.servicebinding.rev160406.service.bindings.services.info.BoundServices;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.LockManagerService;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.TimeUnits;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.TryLockInput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.TryLockInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.UnlockInput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.UnlockInputBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.lockmanager.rev160413.*;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeConnectorRef;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.node.NodeConnector;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.ElanTagNameMap;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.elan.tag.name.map.ElanTagName;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.elan.tag.name.map.ElanTagNameKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.fibentries.VrfTablesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.FibEntries;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.VrfEntryBase;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.extraroute.rds.map.extraroute.rds.dest.prefixes.AllocatedRdsBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.extraroute.rds.map.extraroute.rds.dest.prefixes.AllocatedRdsKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.fibentries.VrfTables;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.fibentries.VrfTablesKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.vrfentries.VrfEntry;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.vrfentries.VrfEntryBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.vrfentries.VrfEntryKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.L3nexthop;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.l3nexthop.VpnNexthops;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.l3nexthop.VpnNexthopsKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.Adjacencies;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.AdjacenciesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.AdjacenciesOp;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.AdjacenciesOpBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.LearntVpnVipToPortData;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.PrefixToInterface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnToExtraroute;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.RouterInterfaces;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.SubnetOpData;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnIdToVpnInstance;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnInstanceOpData;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnInstanceToVpnId;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnInterfaceOpData;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.VpnToExtraroutes;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.adjacency.list.Adjacency;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.Adjacencies;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.AdjacenciesBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.RouterInterfaces;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.adjacency.list.Adjacency.AdjacencyType;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.adjacency.list.AdjacencyKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.learnt.vpn.vip.to.port.data.LearntVpnVipToPort;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.learnt.vpn.vip.to.port.data.LearntVpnVipToPortBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.learnt.vpn.vip.to.port.data.LearntVpnVipToPortKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.VpnIds;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.VpnIdsBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.VpnIdsKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.vpn.ids.Prefixes;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.vpn.ids.PrefixesBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.prefix.to._interface.vpn.ids.PrefixesKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.router.interfaces.RouterInterfaceBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.router.interfaces.RouterInterface;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.router.interfaces.RouterInterfaceBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.router.interfaces.RouterInterfaceKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.subnet.op.data.SubnetOpDataEntry;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.subnet.op.data.SubnetOpDataEntryKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn._interface.op.data.VpnInterfaceOpDataEntry;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn._interface.op.data.VpnInterfaceOpDataEntryBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn._interface.op.data.VpnInterfaceOpDataEntryKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.VpnInstanceOpDataEntry;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.VpnInstanceOpDataEntryBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.VpnInstanceOpDataEntryKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.vpn.instance.op.data.entry.VpnTargets;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.vpn.instance.op.data.entry.VpnToDpnList;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.vpn.instance.op.data.entry.VpnToDpnListKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.vpn.instance.op.data.entry.vpntargets.VpnTarget;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstanceBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.Vpn;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.VpnBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.VpnKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.vpn.Extraroute;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.vpn.ExtrarouteBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroute.vpn.ExtrarouteKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroutes.Vpn;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroutes.VpnKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroutes.vpn.extra.routes.Routes;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.to.extraroutes.vpn.extra.routes.RoutesBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ExtRouters;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ExternalNetworks;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ExternalSubnets;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.NaptSwitches;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers.Routers;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers.RoutersKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers.routers.ExternalIps;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.networks.Networks;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.networks.NetworksKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.FibEntries;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.fibentries.VrfTables;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.fibmanager.rev150330.fibentries.VrfTablesKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdPools;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPool;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPoolKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowCapableNodeConnector;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInput;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdInputBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.AllocateIdOutput;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInput;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInputBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.IdManagerService;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406.IfIndexesInterfaceMap;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406._if.indexes._interface.map.IfIndexInterface;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.meta.rev160406._if.indexes._interface.map.IfIndexInterfaceKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.GetPortFromInterfaceInputBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.GetPortFromInterfaceOutput;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.OdlInterfaceRpcService;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.L3nexthop;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.l3nexthop.VpnNexthops;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3nexthop.rev150409.l3nexthop.VpnNexthopsKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.subnets.SubnetsKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.napt.switches.RouterToNaptSwitch;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.napt.switches.RouterToNaptSwitchKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NetworkMaps;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NeutronVpnPortipPortData;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NeutronvpnService;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.RouterInterfacesMap;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.Subnetmaps;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.networkmaps.NetworkMap;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.networkmaps.NetworkMapKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.neutron.vpn.portip.port.data.VpnPortipToPort;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.neutron.vpn.portip.port.data.VpnPortipToPortBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.neutron.vpn.portip.port.data.VpnPortipToPortKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.subnetmaps.Subnetmap;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.port.attributes.FixedIps;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.Ports;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.subnetmaps.SubnetmapKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.constants.rev150712.IpVersionBase;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.constants.rev150712.IpVersionV4;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.ext.rev150712.NetworkL3Extension;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.networks.rev150712.networks.attributes.networks.Network;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.networks.rev150712.networks.attributes.networks.NetworkKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.ports.Port;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.ports.PortKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.rev150712.Neutron;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.Subnets;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.subnets.Subnet;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.subnets.SubnetKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.inter.vpn.link.rev160311.InterVpnLinkStates;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.inter.vpn.link.rev160311.InterVpnLinks;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.inter.vpn.link.rev160311.inter.vpn.link.states.InterVpnLinkState;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.inter.vpn.link.rev160311.inter.vpn.link.states.InterVpnLinkStateKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.inter.vpn.link.rev160311.inter.vpn.links.InterVpnLink;
+import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier.InstanceIdentifierBuilder;
 import org.opendaylight.yangtools.yang.common.RpcResult;
-import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaValidationFailedException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class VpnUtil {
+public final class VpnUtil {
     private static final Logger LOG = LoggerFactory.getLogger(VpnUtil.class);
     private static final int DEFAULT_PREFIX_LENGTH = 32;
     private static final String PREFIX_SEPARATOR = "/";
 
+    private VpnUtil() {
+    }
+
     static InstanceIdentifier<VpnInterface> getVpnInterfaceIdentifier(String vpnInterfaceName) {
         return InstanceIdentifier.builder(VpnInterfaces.class)
-                .child(VpnInterface.class, new VpnInterfaceKey(vpnInterfaceName)).build();
+            .child(VpnInterface.class, new VpnInterfaceKey(vpnInterfaceName)).build();
+    }
+
+    static InstanceIdentifier<VpnInterfaceOpDataEntry> getVpnInterfaceOpDataEntryIdentifier(
+                                                             String vpnInterfaceName, String vpnName) {
+        return InstanceIdentifier.builder(VpnInterfaceOpData.class)
+            .child(VpnInterfaceOpDataEntry.class,
+            new VpnInterfaceOpDataEntryKey(vpnInterfaceName, vpnName)).build();
     }
 
     static InstanceIdentifier<VpnInstance> getVpnInstanceIdentifier(String vpnName) {
         return InstanceIdentifier.builder(VpnInstances.class)
-                .child(VpnInstance.class, new VpnInstanceKey(vpnName)).build();
+            .child(VpnInstance.class, new VpnInstanceKey(vpnName)).build();
     }
 
-    static VpnInterface getVpnInterface(String intfName, String vpnName, Adjacencies aug, BigInteger dpnId, Boolean isSheduledForRemove) {
-        return new VpnInterfaceBuilder().setKey(new VpnInterfaceKey(intfName)).setVpnInstanceName(vpnName).setDpnId(dpnId)
-                .setScheduledForRemove(isSheduledForRemove).addAugmentation(Adjacencies.class, aug)
-                .build();
+    static VpnInterface getVpnInterface(DataBroker broker, String vpnInterfaceName) {
+        InstanceIdentifier<VpnInterface> id = getVpnInterfaceIdentifier(vpnInterfaceName);
+        Optional<VpnInterface> vpnInterface = read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        return vpnInterface.isPresent() ? vpnInterface.get() : null;
+    }
+
+    static VpnInterfaceOpDataEntry getVpnInterfaceOpDataEntry(String intfName, String vpnName,
+                                        AdjacenciesOp aug, BigInteger dpnId,
+                                        Boolean isSheduledForRemove, long lportTag, String gwMac) {
+        return new VpnInterfaceOpDataEntryBuilder().setKey(new VpnInterfaceOpDataEntryKey(intfName, vpnName))
+            .setDpnId(dpnId).setScheduledForRemove(isSheduledForRemove).addAugmentation(AdjacenciesOp.class, aug)
+                .setLportTag(lportTag).setGatewayMacAddress(gwMac).build();
+    }
+
+    static Optional<VpnInterfaceOpDataEntry> getVpnInterfaceOpDataEntry(DataBroker broker,
+                                                    String vpnInterfaceName, String vpnName) {
+        InstanceIdentifier<VpnInterfaceOpDataEntry> id = getVpnInterfaceOpDataEntryIdentifier(vpnInterfaceName,
+                                                                                              vpnName);
+        Optional<VpnInterfaceOpDataEntry> vpnInterfaceOpDataEntry = read(broker,
+                                                      LogicalDatastoreType.OPERATIONAL, id);
+        return vpnInterfaceOpDataEntry;
+    }
+
+    static VpnInstanceNames getVpnInterfaceVpnInstanceNames(String vpnName, AssociatedSubnetType subnetType) {
+        return new VpnInstanceNamesBuilder().setVpnName(vpnName).setAssociatedSubnetType(subnetType).build();
     }
 
     static InstanceIdentifier<Prefixes> getPrefixToInterfaceIdentifier(long vpnId, String ipPrefix) {
         return InstanceIdentifier.builder(PrefixToInterface.class)
-                .child(VpnIds.class, new VpnIdsKey(vpnId)).child(Prefixes.class,
-                        new PrefixesKey(ipPrefix)).build();
+            .child(VpnIds.class, new VpnIdsKey(vpnId)).child(Prefixes.class,
+                new PrefixesKey(ipPrefix)).build();
     }
 
-    static InstanceIdentifier<VpnIds> getPrefixToInterfaceIdentifier(long vpnId) {
+    public static InstanceIdentifier<VpnIds> getPrefixToInterfaceIdentifier(long vpnId) {
         return InstanceIdentifier.builder(PrefixToInterface.class)
-                .child(VpnIds.class, new VpnIdsKey(vpnId)).build();
+            .child(VpnIds.class, new VpnIdsKey(vpnId)).build();
     }
 
     static VpnIds getPrefixToInterface(long vpnId) {
         return new VpnIdsBuilder().setKey(new VpnIdsKey(vpnId)).setVpnId(vpnId).build();
     }
 
-    static Prefixes getPrefixToInterface(BigInteger dpId, String vpnInterfaceName, String ipPrefix) {
+    static Prefixes getPrefixToInterface(BigInteger dpId, String vpnInterfaceName, String ipPrefix, Uuid subnetId,
+            Prefixes.PrefixCue prefixCue) {
         return new PrefixesBuilder().setDpnId(dpId).setVpnInterfaceName(
-                vpnInterfaceName).setIpAddress(ipPrefix).build();
-    }
-
-    static InstanceIdentifier<Extraroute> getVpnToExtrarouteIdentifier(String vrfId, String ipPrefix) {
-        return InstanceIdentifier.builder(VpnToExtraroute.class)
-                .child(Vpn.class, new VpnKey(vrfId)).child(Extraroute.class,
-                        new ExtrarouteKey(ipPrefix)).build();
-    }
-
-    static InstanceIdentifier<Vpn> getVpnToExtrarouteIdentifier(String vrfId) {
-        return InstanceIdentifier.builder(VpnToExtraroute.class)
-                .child(Vpn.class, new VpnKey(vrfId)).build();
+            vpnInterfaceName).setIpAddress(ipPrefix).setSubnetId(subnetId).setPrefixCue(prefixCue).build();
     }
 
-    static Vpn getVpnToExtraRoute(String vrfId) {
-        return new VpnBuilder().setKey(new VpnKey(vrfId)).setVrfId(vrfId).build();
+    static Optional<Prefixes> getPrefixToInterface(DataBroker broker, long vpnId, String ipPrefix) {
+        return read(broker, LogicalDatastoreType.OPERATIONAL,
+                getPrefixToInterfaceIdentifier(vpnId, getIpPrefix(ipPrefix)));
     }
 
     /**
-     * Get VRF table given a Route Distinguisher
+     * Get VRF table given a Route Distinguisher.
      *
      * @param broker dataBroker service reference
      * @param rd Route-Distinguisher
@@ -231,24 +288,23 @@ public class VpnUtil {
      */
     public static VrfTables getVrfTable(DataBroker broker, String rd) {
         InstanceIdentifier<VrfTables> id =
-                InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
+            InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
         Optional<VrfTables> vrfTable = read(broker, LogicalDatastoreType.CONFIGURATION, id);
         return vrfTable.isPresent() ? vrfTable.get() : null;
     }
 
     /**
      * Retrieves the VrfEntries that belong to a given VPN filtered out by
-     * Origin, searching by its Route-Distinguisher
+     * Origin, searching by its Route-Distinguisher.
      *
      * @param broker dataBroker service reference
-     * @param rd     Route-distinguisher of the VPN
-     * @param originsToConsider Only entries whose origin is included in this
-     *     list will be considered
+     * @param rd Route-distinguisher of the VPN
+     * @param originsToConsider Only entries whose origin is included in this list will be considered
      * @return the list of VrfEntries
      */
     public static List<VrfEntry> getVrfEntriesByOrigin(DataBroker broker, String rd,
-                                                       List<RouteOrigin> originsToConsider) {
-        List<VrfEntry> result = new ArrayList<VrfEntry>();
+        List<RouteOrigin> originsToConsider) {
+        List<VrfEntry> result = new ArrayList<>();
         List<VrfEntry> allVpnVrfEntries = getAllVrfEntries(broker, rd);
         for (VrfEntry vrfEntry : allVpnVrfEntries) {
             if (originsToConsider.contains(RouteOrigin.value(vrfEntry.getOrigin()))) {
@@ -263,77 +319,55 @@ public class VpnUtil {
         if (vpnIds.isPresent()) {
             return vpnIds.get().getPrefixes();
         }
-        return new ArrayList<Prefixes>();
-    }
-
-    static List<Extraroute> getAllExtraRoutes(DataBroker broker, String vrfId) {
-        Optional<Vpn> extraRoutes = read(broker, LogicalDatastoreType.OPERATIONAL, getVpnToExtrarouteIdentifier(vrfId));
-        if (extraRoutes.isPresent()) {
-            return extraRoutes.get().getExtraroute();
-        }
-        return new ArrayList<Extraroute>();
+        return new ArrayList<>();
     }
 
     /**
      * Retrieves all the VrfEntries that belong to a given VPN searching by its
-     * Route-Distinguisher
+     * Route-Distinguisher.
      *
      * @param broker dataBroker service reference
-     * @param rd     Route-distinguisher of the VPN
+     * @param rd Route-distinguisher of the VPN
      * @return the list of VrfEntries
      */
     public static List<VrfEntry> getAllVrfEntries(DataBroker broker, String rd) {
         VrfTables vrfTables = VpnUtil.getVrfTable(broker, rd);
-        return (vrfTables != null) ? vrfTables.getVrfEntry() : new ArrayList<VrfEntry>();
+        return vrfTables != null ? vrfTables.getVrfEntry() : new ArrayList<>();
     }
 
     //FIXME: Implement caches for DS reads
     public static VpnInstance getVpnInstance(DataBroker broker, String vpnInstanceName) {
         InstanceIdentifier<VpnInstance> id = InstanceIdentifier.builder(VpnInstances.class).child(VpnInstance.class,
-                new VpnInstanceKey(vpnInstanceName)).build();
+            new VpnInstanceKey(vpnInstanceName)).build();
         Optional<VpnInstance> vpnInstance = read(broker, LogicalDatastoreType.CONFIGURATION, id);
-        return (vpnInstance.isPresent()) ? vpnInstance.get() : null;
+        return vpnInstance.isPresent() ? vpnInstance.get() : null;
     }
 
-    static List<VpnInstance> getAllVpnInstances(DataBroker broker) {
-        InstanceIdentifier<VpnInstances> id = InstanceIdentifier.builder(VpnInstances.class).build();
-        Optional<VpnInstances> optVpnInstances = VpnUtil.read(broker, LogicalDatastoreType.CONFIGURATION, id);
-        if (optVpnInstances.isPresent()) {
-            return optVpnInstances.get().getVpnInstance();
-        } else {
-            return Collections.emptyList();
-        }
-    }
-
-    static List<VpnInstanceOpDataEntry> getAllVpnInstanceOpData(DataBroker broker) {
+    public static List<VpnInstanceOpDataEntry> getAllVpnInstanceOpData(DataBroker broker) {
         InstanceIdentifier<VpnInstanceOpData> id = InstanceIdentifier.builder(VpnInstanceOpData.class).build();
-        Optional<VpnInstanceOpData> vpnInstanceOpDataOptional = VpnUtil.read(broker, LogicalDatastoreType.OPERATIONAL, id);
+        Optional<VpnInstanceOpData> vpnInstanceOpDataOptional =
+            VpnUtil.read(broker, LogicalDatastoreType.OPERATIONAL, id);
         if (vpnInstanceOpDataOptional.isPresent()) {
             return vpnInstanceOpDataOptional.get().getVpnInstanceOpDataEntry();
         } else {
-            return new ArrayList<VpnInstanceOpDataEntry>();
+            return new ArrayList<>();
         }
     }
 
     public static List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.op.data.vpn
-            .instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces> getDpnVpnInterfaces(DataBroker broker,
-                    VpnInstance vpnInstance, BigInteger dpnId) {
-        String rd = getRdFromVpnInstance(vpnInstance);
-        InstanceIdentifier<VpnToDpnList> dpnToVpnId = getVpnToDpnListIdentifier(rd, dpnId);
+        .instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces> getDpnVpnInterfaces(DataBroker broker,
+        VpnInstance vpnInstance, BigInteger dpnId) {
+        String primaryRd = getPrimaryRd(vpnInstance);
+        InstanceIdentifier<VpnToDpnList> dpnToVpnId = getVpnToDpnListIdentifier(primaryRd, dpnId);
         Optional<VpnToDpnList> dpnInVpn = VpnUtil.read(broker, LogicalDatastoreType.OPERATIONAL, dpnToVpnId);
         return dpnInVpn.isPresent() ? dpnInVpn.get().getVpnInterfaces() : Collections.emptyList();
     }
 
-    public static String getRdFromVpnInstance(VpnInstance vpnInstance) {
+    public static List<String> getListOfRdsFromVpnInstance(VpnInstance vpnInstance) {
         VpnAfConfig vpnConfig = vpnInstance.getIpv4Family();
         LOG.trace("vpnConfig {}", vpnConfig);
-        String rd = vpnConfig.getRouteDistinguisher();
-        if (rd == null || rd.isEmpty()) {
-            rd = vpnInstance.getVpnInstanceName();
-            LOG.trace("rd is null or empty. Assigning VpnInstanceName to rd {}", rd);
-        }
-
-        return rd;
+        return vpnConfig.getRouteDistinguisher() != null ? new ArrayList<>(
+                vpnConfig.getRouteDistinguisher()) : new ArrayList<>();
     }
 
     static VrfEntry getVrfEntry(DataBroker broker, String rd, String ipPrefix) {
@@ -342,8 +376,8 @@ public class VpnUtil {
         // TODO: why check VrfTables if we later go for the specific VrfEntry?
         if (vrfTable != null) {
             InstanceIdentifier<VrfEntry> vrfEntryId =
-                    InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).
-                            child(VrfEntry.class, new VrfEntryKey(ipPrefix)).build();
+                InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).child(
+                    VrfEntry.class, new VrfEntryKey(ipPrefix)).build();
             Optional<VrfEntry> vrfEntry = read(broker, LogicalDatastoreType.CONFIGURATION, vrfEntryId);
             if (vrfEntry.isPresent()) {
                 return vrfEntry.get();
@@ -364,26 +398,43 @@ public class VpnUtil {
         return null;
     }
 
-    static Extraroute getVpnToExtraroute(String ipPrefix, List<String> nextHopList) {
-        return new ExtrarouteBuilder().setPrefix(ipPrefix).setNexthopIpList(nextHopList).build();
+    static  Routes getVpnToExtraroute(String ipPrefix, List<String> nextHopList) {
+        return new RoutesBuilder().setPrefix(ipPrefix).setNexthopIpList(nextHopList).build();
     }
 
-    public static List<Extraroute> getVpnExtraroutes(DataBroker broker, String vpnRd) {
-        InstanceIdentifier<Vpn> vpnExtraRoutesId =
-                InstanceIdentifier.builder(VpnToExtraroute.class).child(Vpn.class, new VpnKey(vpnRd)).build();
-        Optional<Vpn> vpnOpc = read(broker, LogicalDatastoreType.OPERATIONAL, vpnExtraRoutesId);
-        return vpnOpc.isPresent() ? vpnOpc.get().getExtraroute() : new ArrayList<Extraroute>();
+    static String getVpnInterfaceName(OdlInterfaceRpcService odlInterfaceRpcService, BigInteger metadata)
+            throws InterruptedException, ExecutionException {
+        GetInterfaceFromIfIndexInputBuilder ifIndexInputBuilder = new GetInterfaceFromIfIndexInputBuilder();
+        BigInteger lportTag = MetaDataUtil.getLportFromMetadata(metadata);
+        ifIndexInputBuilder.setIfIndex(lportTag.intValue());
+        GetInterfaceFromIfIndexInput input = ifIndexInputBuilder.build();
+        Future<RpcResult<GetInterfaceFromIfIndexOutput>> interfaceFromIfIndex =
+                odlInterfaceRpcService.getInterfaceFromIfIndex(input);
+        GetInterfaceFromIfIndexOutput interfaceFromIfIndexOutput;
+        RpcResult<GetInterfaceFromIfIndexOutput> rpcResult = interfaceFromIfIndex.get();
+        if (rpcResult == null) {
+            return null;
+        }
+        interfaceFromIfIndexOutput = rpcResult.getResult();
+        return interfaceFromIfIndexOutput.getInterfaceName();
+    }
+
+    static AllocatedRdsBuilder getRdsBuilder(String nexthop, String rd) {
+        return new AllocatedRdsBuilder().setKey(new AllocatedRdsKey(nexthop)).setNexthop(nexthop).setRd(rd);
     }
 
     static Adjacencies getVpnInterfaceAugmentation(List<Adjacency> nextHopList) {
         return new AdjacenciesBuilder().setAdjacency(nextHopList).build();
     }
 
+    static AdjacenciesOp getVpnInterfaceOpDataEntryAugmentation(List<Adjacency> nextHopList) {
+        return new AdjacenciesOpBuilder().setAdjacency(nextHopList).build();
+    }
+
     public static InstanceIdentifier<IdPool> getPoolId(String poolName) {
         InstanceIdentifier.InstanceIdentifierBuilder<IdPool> idBuilder =
-                InstanceIdentifier.builder(IdPools.class).child(IdPool.class, new IdPoolKey(poolName));
-        InstanceIdentifier<IdPool> id = idBuilder.build();
-        return id;
+            InstanceIdentifier.builder(IdPools.class).child(IdPool.class, new IdPoolKey(poolName));
+        return idBuilder.build();
     }
 
     static InstanceIdentifier<VpnInterfaces> getVpnInterfacesIdentifier() {
@@ -392,28 +443,28 @@ public class VpnUtil {
 
     static InstanceIdentifier<Interface> getInterfaceIdentifier(String interfaceName) {
         return InstanceIdentifier.builder(Interfaces.class)
-                .child(Interface.class, new InterfaceKey(interfaceName)).build();
+            .child(Interface.class, new InterfaceKey(interfaceName)).build();
     }
 
     static InstanceIdentifier<VpnToDpnList> getVpnToDpnListIdentifier(String rd, BigInteger dpnId) {
         return InstanceIdentifier.builder(VpnInstanceOpData.class)
-                .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(rd))
-                .child(VpnToDpnList.class, new VpnToDpnListKey(dpnId)).build();
+            .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(rd))
+            .child(VpnToDpnList.class, new VpnToDpnListKey(dpnId)).build();
     }
 
     public static BigInteger getCookieArpFlow(int interfaceTag) {
         return VpnConstants.COOKIE_L3_BASE.add(new BigInteger("0110000", 16)).add(
-                BigInteger.valueOf(interfaceTag));
+            BigInteger.valueOf(interfaceTag));
     }
 
     public static BigInteger getCookieL3(int vpnId) {
         return VpnConstants.COOKIE_L3_BASE.add(new BigInteger("0610000", 16)).add(BigInteger.valueOf(vpnId));
     }
 
-    public static String getFlowRef(BigInteger dpnId, short tableId, int ethType, int lPortTag, int arpType) {
+    public static String getFlowRef(BigInteger dpnId, short tableId, int ethType, int lportTag, int arpType) {
         return new StringBuffer().append(VpnConstants.FLOWID_PREFIX).append(dpnId).append(NwConstants.FLOWID_SEPARATOR)
-                .append(tableId).append(NwConstants.FLOWID_SEPARATOR).append(ethType).append(lPortTag)
-                .append(NwConstants.FLOWID_SEPARATOR).append(arpType).toString();
+            .append(tableId).append(NwConstants.FLOWID_SEPARATOR).append(ethType).append(lportTag)
+            .append(NwConstants.FLOWID_SEPARATOR).append(arpType).toString();
     }
 
     public static int getUniqueId(IdManagerService idManager, String poolName, String idKey) {
@@ -425,10 +476,11 @@ public class VpnUtil {
             if (rpcResult.isSuccessful()) {
                 return rpcResult.getResult().getIdValue().intValue();
             } else {
-                LOG.warn("RPC Call to Get Unique Id returned with Errors {}", rpcResult.getErrors());
+                LOG.error("getUniqueId: RPC Call to Get Unique Id from pool {} with key {} returned with Errors {}",
+                        poolName, idKey, rpcResult.getErrors());
             }
         } catch (InterruptedException | ExecutionException e) {
-            LOG.warn("Exception when getting Unique Id", e);
+            LOG.error("getUniqueId: Exception when getting Unique Id from pool {} for key {}", poolName, idKey, e);
         }
         return 0;
     }
@@ -439,10 +491,11 @@ public class VpnUtil {
             Future<RpcResult<Void>> result = idManager.releaseId(idInput);
             RpcResult<Void> rpcResult = result.get();
             if (!rpcResult.isSuccessful()) {
-                LOG.warn("RPC Call to Get Unique Id returned with Errors {}", rpcResult.getErrors());
+                LOG.error("releaseId: RPC Call to release Id for key {} from pool {} returned with Errors {}",
+                        idKey, poolName, rpcResult.getErrors());
             }
         } catch (InterruptedException | ExecutionException e) {
-            LOG.warn("Exception when getting Unique Id for key {}", idKey, e);
+            LOG.error("releaseId: Exception when releasing Id for key {} from pool {}", idKey, poolName, e);
         }
     }
 
@@ -452,7 +505,7 @@ public class VpnUtil {
 
     /**
      * Retrieves the VpnInstance name (typically the VPN Uuid) out from the
-     * route-distinguisher
+     * route-distinguisher.
      *
      * @param broker dataBroker service reference
      * @param rd Route-Distinguisher
@@ -460,7 +513,7 @@ public class VpnUtil {
      */
     public static String getVpnNameFromRd(DataBroker broker, String rd) {
         VpnInstanceOpDataEntry vpnInstanceOpData = getVpnInstanceOpData(broker, rd);
-        return (vpnInstanceOpData != null) ? vpnInstanceOpData.getVpnInstanceName() : null;
+        return vpnInstanceOpData != null ? vpnInstanceOpData.getVpnInstanceName() : null;
     }
 
     /**
@@ -472,31 +525,40 @@ public class VpnUtil {
      * @return the dataplane identifier of the VPN, the VrfTag.
      */
     public static long getVpnId(DataBroker broker, String vpnName) {
+        if (vpnName == null) {
+            return VpnConstants.INVALID_ID;
+        }
 
-        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance> id
-                = getVpnInstanceToVpnIdIdentifier(vpnName);
-        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance> vpnInstance
-                = read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        return read(broker, LogicalDatastoreType.CONFIGURATION,
+                VpnOperDsUtils.getVpnInstanceToVpnIdIdentifier(vpnName)).toJavaUtil().map(
+                org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id
+                        .VpnInstance::getVpnId).orElse(VpnConstants.INVALID_ID);
+    }
 
-        long vpnId = VpnConstants.INVALID_ID;
-        if (vpnInstance.isPresent()) {
-            vpnId = vpnInstance.get().getVpnId();
-        }
-        return vpnId;
+    public static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance
+                        .to.vpn.id.VpnInstance> getVpnInstanceToVpnIdIdentifier(
+            String vpnName) {
+        return InstanceIdentifier.builder(VpnInstanceToVpnId.class)
+                .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id
+                          .VpnInstance.class,
+                        new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn
+                               .id.VpnInstanceKey(
+                                vpnName))
+                .build();
     }
 
     /**
-     * Retrieves the VPN Route Distinguisher searching by its Vpn instance name
+     * Retrieves the VPN Route Distinguisher searching by its Vpn instance name.
      *
      * @param broker dataBroker service reference
      * @param vpnName Name of the VPN
      * @return the route-distinguisher of the VPN
      */
     public static String getVpnRd(DataBroker broker, String vpnName) {
-        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance> id
-                = getVpnInstanceToVpnIdIdentifier(vpnName);
-        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance> vpnInstance
-                = read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id
+            .VpnInstance>
+            vpnInstance
+            = read(broker, LogicalDatastoreType.CONFIGURATION, VpnOperDsUtils.getVpnInstanceToVpnIdIdentifier(vpnName));
 
         String rd = null;
         if (vpnInstance.isPresent()) {
@@ -505,61 +567,50 @@ public class VpnUtil {
         return rd;
     }
 
-    /**
-     * Get VPN Route Distinguisher from VPN Instance Configuration
-     *
-     * @param broker dataBroker service reference
-     * @param vpnName Name of the VPN
-     * @return the route-distinguisher of the VPN
-     */
-    public static String getVpnRdFromVpnInstanceConfig(DataBroker broker, String vpnName) {
+    private static List<String> getVpnRdsFromVpnInstanceConfig(DataBroker broker, String vpnName) {
         InstanceIdentifier<VpnInstance> id = InstanceIdentifier.builder(VpnInstances.class)
-                .child(VpnInstance.class, new VpnInstanceKey(vpnName)).build();
+            .child(VpnInstance.class, new VpnInstanceKey(vpnName)).build();
         Optional<VpnInstance> vpnInstance = VpnUtil.read(broker, LogicalDatastoreType.CONFIGURATION, id);
-        String rd = null;
-        if (vpnInstance.isPresent()) {
-            VpnInstance instance = vpnInstance.get();
-            VpnAfConfig config = instance.getIpv4Family();
-            rd = config.getRouteDistinguisher();
-        }
-        return rd;
+        return vpnInstance.isPresent() ? getListOfRdsFromVpnInstance(vpnInstance.get()) : new ArrayList<>();
     }
 
     /**
-     * Remove from MDSAL all those VrfEntries in a VPN that have an specific RouteOrigin
+     * Remove from MDSAL all those VrfEntries in a VPN that have an specific RouteOrigin.
      *
      * @param broker dataBroker service reference
-     * @param rd     Route Distinguisher
+     * @param rd Route Distinguisher
      * @param origin Origin of the Routes to be removed (see {@link RouteOrigin})
      */
     public static void removeVrfEntriesByOrigin(DataBroker broker, String rd, RouteOrigin origin) {
         InstanceIdentifier<VrfTables> vpnVrfTableIid =
-                InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
+            InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
         Optional<VrfTables> vrfTablesOpc = read(broker, LogicalDatastoreType.CONFIGURATION, vpnVrfTableIid);
         if (vrfTablesOpc.isPresent()) {
             VrfTables vrfTables = vrfTablesOpc.get();
-            List<VrfEntry> newVrfEntries = new ArrayList<VrfEntry>();
+            WriteTransaction tx = broker.newWriteOnlyTransaction();
             for (VrfEntry vrfEntry : vrfTables.getVrfEntry()) {
                 if (origin == RouteOrigin.value(vrfEntry.getOrigin())) {
-                    delete(broker, LogicalDatastoreType.CONFIGURATION, vpnVrfTableIid.child(VrfEntry.class,
-                            vrfEntry.getKey()));
+                    tx.delete(LogicalDatastoreType.CONFIGURATION,
+                            vpnVrfTableIid.child(VrfEntry.class, vrfEntry.getKey()));
                 }
             }
+            tx.submit();
         }
     }
 
     public static List<VrfEntry> findVrfEntriesByNexthop(DataBroker broker, String rd, String nexthop) {
         InstanceIdentifier<VrfTables> vpnVrfTableIid =
-                InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
+            InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
         Optional<VrfTables> vrfTablesOpc = read(broker, LogicalDatastoreType.CONFIGURATION, vpnVrfTableIid);
-        List<VrfEntry> matches = new ArrayList<VrfEntry>();
+        List<VrfEntry> matches = new ArrayList<>();
 
         if (vrfTablesOpc.isPresent()) {
             VrfTables vrfTables = vrfTablesOpc.get();
             for (VrfEntry vrfEntry : vrfTables.getVrfEntry()) {
-                if (vrfEntry.getNextHopAddressList() != null && vrfEntry.getNextHopAddressList().contains(nexthop)) {
-                    matches.add(vrfEntry);
-                }
+                vrfEntry.getRoutePaths().stream()
+                        .filter(routePath -> routePath.getNexthopAddress() != null
+                                && routePath.getNexthopAddress().equals(nexthop))
+                        .findFirst().ifPresent(routePath -> matches.add(vrfEntry));
             }
         }
         return matches;
@@ -568,46 +619,58 @@ public class VpnUtil {
     public static void removeVrfEntries(DataBroker broker, String rd, List<VrfEntry> vrfEntries) {
         InstanceIdentifier<VrfTables> vpnVrfTableIid =
             InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(rd)).build();
+        WriteTransaction tx = broker.newWriteOnlyTransaction();
         for (VrfEntry vrfEntry : vrfEntries) {
-            delete(broker, LogicalDatastoreType.CONFIGURATION, vpnVrfTableIid.child(VrfEntry.class,
-                                                                                    vrfEntry.getKey()));
+            tx.delete(LogicalDatastoreType.CONFIGURATION, vpnVrfTableIid.child(VrfEntry.class, vrfEntry.getKey()));
         }
+        tx.submit();
     }
 
-    static org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance
-                getVpnInstanceToVpnId(String vpnName, long vpnId, String rd) {
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
+    public static void withdrawRoutes(IBgpManager bgpManager, String rd, List<VrfEntry> vrfEntries) {
+        vrfEntries.forEach(vrfEntry -> {
+            try {
+                bgpManager.withdrawPrefix(rd, vrfEntry.getDestPrefix());
+            } catch (Exception e) {
+                LOG.error("withdrawRoutes: Could not withdraw route to {} with route-paths {} in VpnRd {}",
+                          vrfEntry.getDestPrefix(), vrfEntry.getRoutePaths(), rd);
+            }
+        });
+    }
 
+    static org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance
+        getVpnInstanceToVpnId(String vpnName, long vpnId, String rd) {
         return new VpnInstanceBuilder().setVpnId(vpnId).setVpnInstanceName(vpnName).setVrfId(rd).build();
 
     }
 
-    static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance>
-                getVpnInstanceToVpnIdIdentifier(String vpnName) {
-        return InstanceIdentifier.builder(VpnInstanceToVpnId.class)
-                .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstance.class,
-                        new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id.VpnInstanceKey(vpnName)).build();
-    }
-
     static RouterInterface getConfiguredRouterInterface(DataBroker broker, String interfaceName) {
-        Optional<RouterInterface> optRouterInterface = read(broker, LogicalDatastoreType.CONFIGURATION, VpnUtil.getRouterInterfaceId(interfaceName));
-        if(optRouterInterface.isPresent()) {
+        Optional<RouterInterface> optRouterInterface =
+            read(broker, LogicalDatastoreType.CONFIGURATION, VpnUtil.getRouterInterfaceId(interfaceName));
+        if (optRouterInterface.isPresent()) {
             return optRouterInterface.get();
         }
         return null;
     }
 
     static org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds
-                getVpnIdToVpnInstance(long vpnId, String vpnName, String rd, boolean isExternalVpn) {
-        return new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIdsBuilder()
-                .setVpnId(vpnId).setVpnInstanceName(vpnName).setVrfId(rd).setExternalVpn(isExternalVpn).build();
+        getVpnIdToVpnInstance(long vpnId, String vpnName, String rd, boolean isExternalVpn) {
+        return new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance
+            .VpnIdsBuilder()
+            .setVpnId(vpnId).setVpnInstanceName(vpnName).setVrfId(rd).setExternalVpn(isExternalVpn).build();
 
     }
 
-    public static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds>
+    public static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to
+        .vpn.instance.VpnIds>
         getVpnIdToVpnInstanceIdentifier(long vpnId) {
         return InstanceIdentifier.builder(VpnIdToVpnInstance.class)
-                .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds.class,
-                        new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIdsKey(Long.valueOf(vpnId))).build();
+            .child(
+                org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds
+                    .class,
+                new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance
+                    .VpnIdsKey(vpnId)).build();
     }
 
     /**
@@ -619,10 +682,13 @@ public class VpnUtil {
      */
     public static String getVpnName(DataBroker broker, long vpnId) {
 
-        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds> id
-                = getVpnIdToVpnInstanceIdentifier(vpnId);
-        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds> vpnInstance
-                = read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn
+            .instance.VpnIds>
+            id
+            = getVpnIdToVpnInstanceIdentifier(vpnId);
+        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds>
+            vpnInstance
+            = read(broker, LogicalDatastoreType.CONFIGURATION, id);
 
         String vpnName = null;
         if (vpnInstance.isPresent()) {
@@ -633,31 +699,28 @@ public class VpnUtil {
 
     public static InstanceIdentifier<VpnInstanceOpDataEntry> getVpnInstanceOpDataIdentifier(String rd) {
         return InstanceIdentifier.builder(VpnInstanceOpData.class)
-                .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(rd)).build();
+            .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(rd)).build();
     }
 
     static InstanceIdentifier<RouterInterface> getRouterInterfaceId(String interfaceName) {
         return InstanceIdentifier.builder(RouterInterfaces.class)
-                .child(RouterInterface.class, new RouterInterfaceKey(interfaceName)).build();
+            .child(RouterInterface.class, new RouterInterfaceKey(interfaceName)).build();
     }
 
     static RouterInterface getRouterInterface(String interfaceName, String routerName) {
         return new RouterInterfaceBuilder().setKey(new RouterInterfaceKey(interfaceName))
-                .setInterfaceName(interfaceName).setRouterName(routerName).build();
+            .setInterfaceName(interfaceName).setRouterName(routerName).build();
     }
 
-    static VpnInstanceOpDataEntry getVpnInstanceOpData(DataBroker broker, String rd) {
+    public static VpnInstanceOpDataEntry getVpnInstanceOpData(DataBroker broker, String rd) {
         InstanceIdentifier<VpnInstanceOpDataEntry> id = VpnUtil.getVpnInstanceOpDataIdentifier(rd);
-        Optional<VpnInstanceOpDataEntry> vpnInstanceOpData = read(broker, LogicalDatastoreType.OPERATIONAL, id);
-        if (vpnInstanceOpData.isPresent()) {
-            return vpnInstanceOpData.get();
-        }
-        return null;
+        return read(broker, LogicalDatastoreType.OPERATIONAL, id).orNull();
     }
 
     static VpnInstanceOpDataEntry getVpnInstanceOpDataFromCache(DataBroker broker, String rd) {
         InstanceIdentifier<VpnInstanceOpDataEntry> id = VpnUtil.getVpnInstanceOpDataIdentifier(rd);
-        return (VpnInstanceOpDataEntry) DataStoreCache.get(VpnConstants.VPN_OP_INSTANCE_CACHE_NAME, id, rd, broker, false);
+        return (VpnInstanceOpDataEntry) DataStoreCache.get(VpnConstants.VPN_OP_INSTANCE_CACHE_NAME, id, rd, broker,
+            false);
     }
 
     static VpnInterface getConfiguredVpnInterface(DataBroker broker, String interfaceName) {
@@ -672,58 +735,60 @@ public class VpnUtil {
 
     static String getNeutronRouterFromInterface(DataBroker broker, String interfaceName) {
         InstanceIdentifier.InstanceIdentifierBuilder<RouterInterfacesMap> idBuilder =
-                            InstanceIdentifier.builder(RouterInterfacesMap.class);
+            InstanceIdentifier.builder(RouterInterfacesMap.class);
         InstanceIdentifier<RouterInterfacesMap> id = idBuilder.build();
-        Optional<RouterInterfacesMap> RouterInterfacesMap = MDSALUtil.read(broker, LogicalDatastoreType.CONFIGURATION, id);
-        if (RouterInterfacesMap.isPresent()) {
-              List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map.RouterInterfaces> rtrInterfaces = RouterInterfacesMap.get().getRouterInterfaces();
-              for (org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map.RouterInterfaces rtrInterface : rtrInterfaces) {
-                  List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map.router.interfaces.Interfaces> rtrIfc = rtrInterface.getInterfaces();
-                  for(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map.router.interfaces.Interfaces ifc : rtrIfc) {
-                      if (ifc.getInterfaceId().equals(interfaceName)) {
-                          return rtrInterface.getRouterId().getValue();
-                      }
-                  }
-              }
-        }
-        return null;
-    }
-
-    static VpnInterface getOperationalVpnInterface(DataBroker broker, String interfaceName) {
-        InstanceIdentifier<VpnInterface> interfaceId = getVpnInterfaceIdentifier(interfaceName);
-        Optional<VpnInterface> operationalVpnInterface = read(broker, LogicalDatastoreType.OPERATIONAL, interfaceId);
-
-        if (operationalVpnInterface.isPresent()) {
-            return operationalVpnInterface.get();
+        Optional<RouterInterfacesMap> routerInterfacesMap =
+            MDSALUtil.read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        if (routerInterfacesMap.isPresent()) {
+            List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map
+                .RouterInterfaces>
+                rtrInterfaces = routerInterfacesMap.get().getRouterInterfaces();
+            for (org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map
+                     .RouterInterfaces rtrInterface : rtrInterfaces) {
+                List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map
+                    .router.interfaces.Interfaces>
+                    rtrIfc = rtrInterface.getInterfaces();
+                for (org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.router.interfaces.map
+                         .router.interfaces.Interfaces ifc : rtrIfc) {
+                    if (ifc.getInterfaceId().equals(interfaceName)) {
+                        return rtrInterface.getRouterId().getValue();
+                    }
+                }
+            }
         }
         return null;
     }
 
     static boolean isVpnInterfaceConfigured(DataBroker broker, String interfaceName) {
         InstanceIdentifier<VpnInterface> interfaceId = getVpnInterfaceIdentifier(interfaceName);
-        Optional<VpnInterface> configuredVpnInterface = read(broker, LogicalDatastoreType.CONFIGURATION, interfaceId);
-
-        if (configuredVpnInterface.isPresent()) {
-            return true;
-        }
-        return false;
+        return read(broker, LogicalDatastoreType.CONFIGURATION, interfaceId).isPresent();
     }
 
-    static boolean isInterfaceAssociatedWithVpn(DataBroker broker, String vpnName, String interfaceName) {
+    static Optional<List<String>> getVpnHandlingIpv4AssociatedWithInterface(DataBroker broker, String interfaceName) {
         InstanceIdentifier<VpnInterface> interfaceId = getVpnInterfaceIdentifier(interfaceName);
-        Optional<VpnInterface> optConfiguredVpnInterface = read(broker, LogicalDatastoreType.CONFIGURATION, interfaceId);
-
+        Optional<List<String>> vpnOptional = Optional.absent();
+        Optional<VpnInterface> optConfiguredVpnInterface = read(broker, LogicalDatastoreType.CONFIGURATION,
+                interfaceId);
         if (optConfiguredVpnInterface.isPresent()) {
-            String configuredVpnName = optConfiguredVpnInterface.get().getVpnInstanceName();
-            if ((configuredVpnName != null) && (configuredVpnName.equalsIgnoreCase(vpnName))) {
-                return true;
+            VpnInterface cfgVpnInterface = optConfiguredVpnInterface.get();
+            java.util.Optional<List<VpnInstanceNames>> optVpnInstanceList =
+                 java.util.Optional.ofNullable(cfgVpnInterface.getVpnInstanceNames());
+            if (optVpnInstanceList.isPresent()) {
+                List<String> vpnList = new ArrayList<>();
+                for (VpnInstanceNames vpnInstance : optVpnInstanceList.get()) {
+                    if (vpnInstance.getAssociatedSubnetType().equals(AssociatedSubnetType.V6Subnet)) {
+                        continue;
+                    }
+                    vpnList.add(vpnInstance.getVpnName());
+                }
+                vpnOptional = Optional.of(vpnList);
             }
         }
-        return false;
+        return vpnOptional;
     }
 
-    static String getIpPrefix(String prefix) {
-        String prefixValues[] = prefix.split("/");
+    public static String getIpPrefix(String prefix) {
+        String[] prefixValues = prefix.split("/");
         if (prefixValues.length == 1) {
             prefix = prefix + PREFIX_SEPARATOR + DEFAULT_PREFIX_LENGTH;
         }
@@ -731,119 +796,113 @@ public class VpnUtil {
     }
 
     static final FutureCallback<Void> DEFAULT_CALLBACK =
-            new FutureCallback<Void>() {
-                @Override
-                public void onSuccess(Void result) {
-                    LOG.debug("Success in Datastore operation");
-                }
+        new FutureCallback<Void>() {
+            @Override
+            public void onSuccess(Void result) {
+                LOG.debug("Success in Datastore operation");
+            }
 
-                @Override
-                public void onFailure(Throwable error) {
-                    LOG.error("Error in Datastore operation", error);
-                }
+            @Override
+            public void onFailure(Throwable error) {
+                LOG.error("Error in Datastore operation", error);
+            }
 
-                ;
-            };
+        };
 
     public static <T extends DataObject> Optional<T> read(DataBroker broker, LogicalDatastoreType datastoreType,
                                                           InstanceIdentifier<T> path) {
-
-        ReadOnlyTransaction tx = broker.newReadOnlyTransaction();
-
-        Optional<T> result = Optional.absent();
-        try {
-            result = tx.read(datastoreType, path).get();
-        } catch (Exception e) {
+        try (ReadOnlyTransaction tx = broker.newReadOnlyTransaction()) {
+            return tx.read(datastoreType, path).get();
+        } catch (InterruptedException | ExecutionException e) {
             throw new RuntimeException(e);
-        } finally {
-            tx.close();
         }
-
-        return result;
     }
 
     public static <T extends DataObject> void asyncUpdate(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                          InstanceIdentifier<T> path, T data) {
+        InstanceIdentifier<T> path, T data) {
         asyncUpdate(broker, datastoreType, path, data, DEFAULT_CALLBACK);
     }
 
     public static <T extends DataObject> void asyncUpdate(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                          InstanceIdentifier<T> path, T data, FutureCallback<Void> callback) {
+        InstanceIdentifier<T> path, T data, FutureCallback<Void> callback) {
         WriteTransaction tx = broker.newWriteOnlyTransaction();
         tx.merge(datastoreType, path, data, true);
-        Futures.addCallback(tx.submit(), callback);
+        Futures.addCallback(tx.submit(), callback, MoreExecutors.directExecutor());
     }
 
     public static <T extends DataObject> void asyncWrite(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                         InstanceIdentifier<T> path, T data) {
+        InstanceIdentifier<T> path, T data) {
         asyncWrite(broker, datastoreType, path, data, DEFAULT_CALLBACK);
     }
 
     public static <T extends DataObject> void asyncWrite(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                         InstanceIdentifier<T> path, T data, FutureCallback<Void> callback) {
+        InstanceIdentifier<T> path, T data, FutureCallback<Void> callback) {
         WriteTransaction tx = broker.newWriteOnlyTransaction();
-        tx.put(datastoreType, path, data, true);
-        Futures.addCallback(tx.submit(), callback);
+        tx.put(datastoreType, path, data, WriteTransaction.CREATE_MISSING_PARENTS);
+        Futures.addCallback(tx.submit(), callback, MoreExecutors.directExecutor());
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static <T extends DataObject> void tryDelete(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                     InstanceIdentifier<T> path) {
+        InstanceIdentifier<T> path) {
         try {
             delete(broker, datastoreType, path, DEFAULT_CALLBACK);
-        } catch ( SchemaValidationFailedException sve ) {
-            LOG.info("Could not delete {}. SchemaValidationFailedException: {}", path, sve.getMessage());
-        } catch ( Exception e) {
-            LOG.info("Could not delete {}. Unhandled error: {}", path, e.getMessage());
+        } catch (SchemaValidationFailedException sve) {
+            LOG.info("tryDelete: Could not delete {}. SchemaValidationFailedException: {}", path, sve.getMessage());
+        } catch (Exception e) {
+            LOG.info("tryDelete: Could not delete {}. Unhandled error: {}", path, e.getMessage());
         }
     }
 
     public static <T extends DataObject> void delete(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                     InstanceIdentifier<T> path) {
+        InstanceIdentifier<T> path) {
         delete(broker, datastoreType, path, DEFAULT_CALLBACK);
     }
 
 
     public static <T extends DataObject> void delete(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                     InstanceIdentifier<T> path, FutureCallback<Void> callback) {
+        InstanceIdentifier<T> path, FutureCallback<Void> callback) {
         WriteTransaction tx = broker.newWriteOnlyTransaction();
         tx.delete(datastoreType, path);
-        Futures.addCallback(tx.submit(), callback);
+        Futures.addCallback(tx.submit(), callback, MoreExecutors.directExecutor());
     }
 
     public static <T extends DataObject> void syncWrite(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                        InstanceIdentifier<T> path, T data) {
+        InstanceIdentifier<T> path, T data) {
         WriteTransaction tx = broker.newWriteOnlyTransaction();
-        tx.put(datastoreType, path, data, true);
-        CheckedFuture<Void, TransactionCommitFailedException> futures = tx.submit();
+        tx.put(datastoreType, path, data, WriteTransaction.CREATE_MISSING_PARENTS);
+
         try {
-            futures.get();
+            tx.submit().get();
         } catch (InterruptedException | ExecutionException e) {
-            LOG.error("Error writing to datastore (path, data) : ({}, {})", path, data);
-            throw new RuntimeException(e.getMessage());
+            LOG.error("syncWrite: Error writing to datastore (path, data) : ({}, {})", path, data);
+            throw new RuntimeException(e.getMessage(), e);
         }
     }
 
     public static <T extends DataObject> void syncUpdate(DataBroker broker, LogicalDatastoreType datastoreType,
-                                                         InstanceIdentifier<T> path, T data) {
+        InstanceIdentifier<T> path, T data) {
         WriteTransaction tx = broker.newWriteOnlyTransaction();
         tx.merge(datastoreType, path, data, true);
-        CheckedFuture<Void, TransactionCommitFailedException> futures = tx.submit();
+
         try {
-            futures.get();
+            tx.submit().get();
         } catch (InterruptedException | ExecutionException e) {
-            LOG.error("Error writing to datastore (path, data) : ({}, {})", path, data);
-            throw new RuntimeException(e.getMessage());
+            LOG.error("syncUpdate: Error writing to datastore (path, data) : ({}, {})", path, data);
+            throw new RuntimeException(e.getMessage(), e);
         }
     }
 
     public static long getRemoteBCGroup(long elanTag) {
-        return VpnConstants.ELAN_GID_MIN + ((elanTag % VpnConstants.ELAN_GID_MIN) * 2);
+        return VpnConstants.ELAN_GID_MIN + elanTag % VpnConstants.ELAN_GID_MIN * 2;
     }
 
     // interface-index-tag operational container
     public static IfIndexInterface getInterfaceInfoByInterfaceTag(DataBroker broker, long interfaceTag) {
         InstanceIdentifier<IfIndexInterface> interfaceId = getInterfaceInfoEntriesOperationalDataPath(interfaceTag);
-        Optional<IfIndexInterface> existingInterfaceInfo = VpnUtil.read(broker, LogicalDatastoreType.OPERATIONAL, interfaceId);
+        Optional<IfIndexInterface> existingInterfaceInfo =
+            VpnUtil.read(broker, LogicalDatastoreType.OPERATIONAL, interfaceId);
         if (existingInterfaceInfo.isPresent()) {
             return existingInterfaceInfo.get();
         }
@@ -852,7 +911,7 @@ public class VpnUtil {
 
     private static InstanceIdentifier<IfIndexInterface> getInterfaceInfoEntriesOperationalDataPath(long interfaceTag) {
         return InstanceIdentifier.builder(IfIndexesInterfaceMap.class).child(IfIndexInterface.class,
-                new IfIndexInterfaceKey((int) interfaceTag)).build();
+            new IfIndexInterfaceKey((int) interfaceTag)).build();
     }
 
     public static ElanTagName getElanInfoByElanTag(DataBroker broker, long elanTag) {
@@ -866,90 +925,76 @@ public class VpnUtil {
 
     private static InstanceIdentifier<ElanTagName> getElanInfoEntriesOperationalDataPath(long elanTag) {
         return InstanceIdentifier.builder(ElanTagNameMap.class).child(ElanTagName.class,
-                new ElanTagNameKey(elanTag)).build();
-    }
-
-
-    // TODO: Move this to NwUtil
-    public static boolean isIpInSubnet(int ipAddress, String subnetCidr) {
-        String[] subSplit = subnetCidr.split("/");
-        if (subSplit.length < 2) {
-            return false;
-        }
-
-        String subnetStr = subSplit[0];
-        int subnet = 0;
-        try {
-            InetAddress subnetAddress = InetAddress.getByName(subnetStr);
-            subnet = Ints.fromByteArray(subnetAddress.getAddress());
-        } catch (Exception ex) {
-            LOG.error("Passed in Subnet IP string not convertible to InetAdddress " + subnetStr);
-            return false;
-        }
-        int prefixLength = Integer.valueOf(subSplit[1]);
-        int mask = -1 << (32 - prefixLength);
-        if ((subnet & mask) == (ipAddress & mask)) {
-            return true;
-        }
-        return false;
+            new ElanTagNameKey(elanTag)).build();
     }
 
     /**
-     * Returns the Path identifier to reach a specific interface in a specific DPN in a given VpnInstance
+     * Returns the Path identifier to reach a specific interface in a specific DPN in a given VpnInstance.
      *
-     * @param vpnRd     Route-Distinguisher of the VpnInstance
-     * @param dpnId     Id of the DPN where the interface is
+     * @param vpnRd Route-Distinguisher of the VpnInstance
+     * @param dpnId Id of the DPN where the interface is
      * @param ifaceName Interface name
      * @return the Instance Identifier
      */
     public static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
-            .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces>
-    getVpnToDpnInterfacePath(String vpnRd, BigInteger dpnId, String ifaceName) {
+        .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces>
+        getVpnToDpnInterfacePath(String vpnRd, BigInteger dpnId, String ifaceName) {
 
         return
-                InstanceIdentifier.builder(VpnInstanceOpData.class)
-                        .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(vpnRd))
-                        .child(VpnToDpnList.class, new VpnToDpnListKey(dpnId))
-                        .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
-                                .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces.class,
-                                new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
-                                        .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfacesKey(ifaceName))
-                        .build();
+            InstanceIdentifier.builder(VpnInstanceOpData.class)
+                .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(vpnRd))
+                .child(VpnToDpnList.class, new VpnToDpnListKey(dpnId))
+                .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
+                        .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfaces.class,
+                    new org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
+                        .instance.op.data.vpn.instance.op.data.entry.vpn.to.dpn.list.VpnInterfacesKey(ifaceName))
+                .build();
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removePrefixToInterfaceForVpnId(DataBroker broker, long vpnId, WriteTransaction writeTxn) {
         try {
             // Clean up PrefixToInterface Operational DS
             if (writeTxn != null) {
                 writeTxn.delete(LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(PrefixToInterface.class).child(
-                                VpnIds.class, new VpnIdsKey(vpnId)).build());
+                    InstanceIdentifier.builder(PrefixToInterface.class).child(
+                        VpnIds.class, new VpnIdsKey(vpnId)).build());
             } else {
                 delete(broker, LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(PrefixToInterface.class).child(VpnIds.class, new VpnIdsKey(vpnId)).build(),
-                        DEFAULT_CALLBACK);
+                    InstanceIdentifier.builder(PrefixToInterface.class).child(VpnIds.class,
+                        new VpnIdsKey(vpnId)).build(),
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during cleanup of PrefixToInterface for VPN ID {}", vpnId, e);
+            LOG.error("removePrefixToInterfaceForVpnId: Exception during cleanup of PrefixToInterface for VPN ID {}",
+                    vpnId, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeVpnExtraRouteForVpn(DataBroker broker, String vpnName, WriteTransaction writeTxn) {
         try {
             // Clean up VPNExtraRoutes Operational DS
             if (writeTxn != null) {
                 writeTxn.delete(LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(VpnToExtraroute.class).child(Vpn.class, new VpnKey(vpnName)).build());
+                        InstanceIdentifier.builder(VpnToExtraroutes.class)
+                                .child(Vpn.class, new VpnKey(vpnName)).build());
             } else {
                 delete(broker, LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(VpnToExtraroute.class).child(Vpn.class, new VpnKey(vpnName)).build(),
+                        InstanceIdentifier.builder(VpnToExtraroutes.class)
+                                .child(Vpn.class, new VpnKey(vpnName)).build(),
                         DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during cleanup of VPNToExtraRoute for VPN {}", vpnName, e);
+            LOG.error("removeVpnExtraRouteForVpna: Exception during cleanup of VPNToExtraRoute for VPN {}",
+                    vpnName, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeVpnOpInstance(DataBroker broker, String vpnName, WriteTransaction writeTxn) {
         try {
             // Clean up VPNInstanceOpDataEntry
@@ -957,145 +1002,98 @@ public class VpnUtil {
                 writeTxn.delete(LogicalDatastoreType.OPERATIONAL, getVpnInstanceOpDataIdentifier(vpnName));
             } else {
                 delete(broker, LogicalDatastoreType.OPERATIONAL, getVpnInstanceOpDataIdentifier(vpnName),
-                        DEFAULT_CALLBACK);
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during cleanup of VPNInstanceOpDataEntry for VPN {}", vpnName, e);
+            LOG.error("removeVpnOpInstance: Exception during cleanup of VPNInstanceOpDataEntry for VPN {}",
+                    vpnName, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeVpnInstanceToVpnId(DataBroker broker, String vpnName, WriteTransaction writeTxn) {
         try {
             if (writeTxn != null) {
-                writeTxn.delete(LogicalDatastoreType.CONFIGURATION, getVpnInstanceToVpnIdIdentifier(vpnName));
+                writeTxn.delete(LogicalDatastoreType.CONFIGURATION,
+                                VpnOperDsUtils.getVpnInstanceToVpnIdIdentifier(vpnName));
             } else {
-                delete(broker, LogicalDatastoreType.CONFIGURATION, getVpnInstanceToVpnIdIdentifier(vpnName),
-                        DEFAULT_CALLBACK);
+                delete(broker, LogicalDatastoreType.CONFIGURATION,
+                       VpnOperDsUtils.getVpnInstanceToVpnIdIdentifier(vpnName),
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during clean up of VpnInstanceToVpnId for VPN {}", vpnName, e);
+            LOG.error("removeVpnInstanceToVpnId: Exception during clean up of VpnInstanceToVpnId for VPN {}",
+                    vpnName, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeVpnIdToVpnInstance(DataBroker broker, long vpnId, WriteTransaction writeTxn) {
         try {
             if (writeTxn != null) {
                 writeTxn.delete(LogicalDatastoreType.CONFIGURATION, getVpnIdToVpnInstanceIdentifier(vpnId));
             } else {
                 delete(broker, LogicalDatastoreType.CONFIGURATION, getVpnIdToVpnInstanceIdentifier(vpnId),
-                        DEFAULT_CALLBACK);
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during clean up of VpnIdToVpnInstance for VPNID {}", vpnId, e);
+            LOG.error("removeVpnIdToVpnInstance: Exception during clean up of VpnIdToVpnInstance for VPNID {}",
+                    vpnId, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeVrfTableForVpn(DataBroker broker, String vpnName, WriteTransaction writeTxn) {
         // Clean up FIB Entries Config DS
         try {
             if (writeTxn != null) {
                 writeTxn.delete(LogicalDatastoreType.CONFIGURATION,
-                        InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(vpnName)).build());
+                    InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class,
+                        new VrfTablesKey(vpnName)).build());
             } else {
                 delete(broker, LogicalDatastoreType.CONFIGURATION,
-                        InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class, new VrfTablesKey(vpnName)).build(),
-                        DEFAULT_CALLBACK);
+                    InstanceIdentifier.builder(FibEntries.class).child(VrfTables.class,
+                        new VrfTablesKey(vpnName)).build(),
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during clean up of VrfTable from FIB for VPN {}", vpnName, e);
+            LOG.error("removeVrfTableForVpn: Exception during clean up of VrfTable from FIB for VPN {}",
+                    vpnName, e);
         }
     }
 
+    // TODO Clean up the exception handling
+    @SuppressWarnings("checkstyle:IllegalCatch")
     public static void removeL3nexthopForVpnId(DataBroker broker, long vpnId, WriteTransaction writeTxn) {
         try {
             // Clean up L3NextHop Operational DS
             if (writeTxn != null) {
                 writeTxn.delete(LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(L3nexthop.class).child(VpnNexthops.class, new VpnNexthopsKey(vpnId)).build());
+                    InstanceIdentifier.builder(L3nexthop.class).child(VpnNexthops.class,
+                        new VpnNexthopsKey(vpnId)).build());
             } else {
                 delete(broker, LogicalDatastoreType.OPERATIONAL,
-                        InstanceIdentifier.builder(L3nexthop.class).child(VpnNexthops.class, new VpnNexthopsKey(vpnId)).build(),
-                        DEFAULT_CALLBACK);
+                    InstanceIdentifier.builder(L3nexthop.class).child(VpnNexthops.class,
+                        new VpnNexthopsKey(vpnId)).build(),
+                    DEFAULT_CALLBACK);
             }
         } catch (Exception e) {
-            LOG.error("Exception during cleanup of L3NextHop for VPN ID {}", vpnId, e);
-        }
-    }
-
-    /**
-     * Retrieves the ids of the currently operative DPNs
-     *
-     * @param dataBroker dataBroker service reference
-     * @return the list of DPNs currently operative
-     */
-    public static List<BigInteger> getOperativeDPNs(DataBroker dataBroker) {
-        List<BigInteger> result = new LinkedList<BigInteger>();
-        InstanceIdentifier<Nodes> nodesInstanceIdentifier = InstanceIdentifier.builder(Nodes.class).build();
-        Optional<Nodes> nodesOptional = MDSALUtil.read(dataBroker, LogicalDatastoreType.OPERATIONAL,
-                nodesInstanceIdentifier);
-        if (!nodesOptional.isPresent()) {
-            return result;
-        }
-        Nodes nodes = nodesOptional.get();
-        List<Node> nodeList = nodes.getNode();
-        for (Node node : nodeList) {
-            NodeId nodeId = node.getId();
-            if (nodeId != null) {
-                BigInteger dpnId = MDSALUtil.getDpnIdFromNodeName(nodeId);
-                result.add(dpnId);
-            }
-        }
-        return result;
-    }
-
-    /**
-     * Retrieves a list of randomly selected DPNs, as many as specified.
-     *
-     * @param dataBroker dataBroker service reference
-     * @param numberOfDPNs Specifies how many Operative DPNs must be found
-     * @param excludingDPNs Specifies a blacklist of DPNs
-     * @return the list of DPN Ids
-     */
-    public static List<BigInteger> pickRandomDPNs(DataBroker dataBroker, int numberOfDPNs,
-                                                  List<BigInteger> excludingDPNs) {
-        List<BigInteger> dpnIdPool = getOperativeDPNs(dataBroker);
-        int poolSize = dpnIdPool.size();
-        if (poolSize <= numberOfDPNs) {
-            // You requested more than there is, I give you all I have.
-            return dpnIdPool;
-        }
-
-        // Random reorder
-        Collections.shuffle(dpnIdPool);
-        List<BigInteger> result = new ArrayList<BigInteger>();
-
-        for (BigInteger dpId : dpnIdPool) {
-            if (excludingDPNs == null || !excludingDPNs.contains(dpId)) {
-                result.add(dpId);
-                if (result.size() == numberOfDPNs) {
-                    break;
-                }
-            }
-        }
-
-        if (result.size() < numberOfDPNs) {
-            // We still don't have all we need, so we have to pick up among the "prohibited" ones
-            dpnIdPool.removeAll(result);
-
-            int nbrOfProhibitedDpnsToPick = numberOfDPNs - result.size();
-            for (int i = 0; i < nbrOfProhibitedDpnsToPick; i++) {
-                result.add(dpnIdPool.get(i));
-            }
+            LOG.error("removeL3nexthopForVpnId: Exception during cleanup of L3NextHop for VPN ID {}", vpnId, e);
         }
-        return result;
     }
 
     public static void scheduleVpnInterfaceForRemoval(DataBroker broker,String interfaceName, BigInteger dpnId,
                                                       String vpnInstanceName, Boolean isScheduledToRemove,
-                                                      WriteTransaction writeOperTxn){
-        InstanceIdentifier<VpnInterface> interfaceId = VpnUtil.getVpnInterfaceIdentifier(interfaceName);
-        VpnInterface interfaceToUpdate = new VpnInterfaceBuilder().setKey(new VpnInterfaceKey(interfaceName)).setName(interfaceName)
-                .setDpnId(dpnId).setVpnInstanceName(vpnInstanceName).setScheduledForRemove(isScheduledToRemove).build();
+                                                      WriteTransaction writeOperTxn) {
+        InstanceIdentifier<VpnInterfaceOpDataEntry> interfaceId =
+            VpnUtil.getVpnInterfaceOpDataEntryIdentifier(interfaceName, vpnInstanceName);
+        VpnInterfaceOpDataEntry interfaceToUpdate =
+            new VpnInterfaceOpDataEntryBuilder().setKey(new VpnInterfaceOpDataEntryKey(interfaceName,
+            vpnInstanceName)).setName(interfaceName).setDpnId(dpnId).setVpnInstanceName(vpnInstanceName)
+            .setScheduledForRemove(isScheduledToRemove).build();
         if (writeOperTxn != null) {
             writeOperTxn.merge(LogicalDatastoreType.OPERATIONAL, interfaceId, interfaceToUpdate, true);
         } else {
@@ -1103,102 +1101,92 @@ public class VpnUtil {
         }
     }
 
-    public static Port getNeutronPortForFloatingIp(DataBroker broker, IpAddress targetIP) {
-        InstanceIdentifier<Ports> portsIdentifier = InstanceIdentifier.create(Neutron.class).child(Ports.class);
-        Optional<Ports> portsOptional = VpnUtil.read(broker, LogicalDatastoreType.CONFIGURATION, portsIdentifier);
-        if (!portsOptional.isPresent() || portsOptional.get().getPort() == null) {
-            LOG.trace("No neutron ports found");
-            return null;
-        }
-
-        for (Port port : portsOptional.get().getPort()) {
-            if (NeutronConstants.DEVICE_OWNER_FLOATING_IP.equals(port.getDeviceOwner()) && port.getFixedIps() != null) {
-                for (FixedIps ip : port.getFixedIps()) {
-                    if (Objects.equals(ip.getIpAddress(), targetIP)) {
-                        return port;
-                    }
-                }
-            }
+    protected static void createLearntVpnVipToPort(DataBroker broker, String vpnName, String fixedIp, String
+            portName, String macAddress) {
+        synchronized ((vpnName + fixedIp).intern()) {
+            InstanceIdentifier<LearntVpnVipToPort> id = buildLearntVpnVipToPortIdentifier(vpnName, fixedIp);
+            LearntVpnVipToPortBuilder builder =
+                    new LearntVpnVipToPortBuilder().setKey(new LearntVpnVipToPortKey(fixedIp, vpnName)).setVpnName(
+                            vpnName).setPortFixedip(fixedIp).setPortName(portName)
+                            .setMacAddress(macAddress.toLowerCase(Locale.getDefault()))
+                            .setCreationTime(new SimpleDateFormat("MM/dd/yyyy h:mm:ss a").format(new Date()));
+            MDSALUtil.syncWrite(broker, LogicalDatastoreType.OPERATIONAL, id, builder.build());
+            LOG.debug("createLearntVpnVipToPort: ARP learned for fixedIp: {}, vpn {}, interface {}, mac {},"
+                    + " isSubnetIp {} added to VpnPortipToPort DS", fixedIp, vpnName, portName, macAddress);
         }
-
-        return null;
     }
 
-    public static boolean isNeutronPortConfigured(DataBroker broker, String portId,
-                                                  org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress targetIP) {
-        InstanceIdentifier<Port> portIdentifier = InstanceIdentifier.create(Neutron.class).
-                child(Ports.class).child(Port.class, new PortKey(new Uuid(portId)));
-        Optional<Port> optPort = VpnUtil.read(broker, LogicalDatastoreType.CONFIGURATION, portIdentifier);
-        if (optPort.isPresent()) {
-            Port port = optPort.get();
-            for (FixedIps ip : port.getFixedIps()) {
-                if (Objects.equals(ip.getIpAddress(), targetIP)) {
-                    return true;
-                }
-            }
-        }
-
-        LOG.trace("No neutron ports found matching portId {} with targetIp {}", portId, targetIP);
-        return false;
+    private static InstanceIdentifier<LearntVpnVipToPort> buildLearntVpnVipToPortIdentifier(String vpnName,
+            String fixedIp) {
+        InstanceIdentifier<LearntVpnVipToPort> id =
+                InstanceIdentifier.builder(LearntVpnVipToPortData.class).child(LearntVpnVipToPort.class,
+                        new LearntVpnVipToPortKey(fixedIp, vpnName)).build();
+        return id;
     }
 
-    protected static void createVpnPortFixedIpToPort(DataBroker broker, String vpnName, String fixedIp, String
-            portName, String macAddress, boolean isSubnetIp, boolean isConfig, boolean isLearnt) {
+    protected static void removeLearntVpnVipToPort(DataBroker broker, String vpnName, String fixedIp) {
         synchronized ((vpnName + fixedIp).intern()) {
-            InstanceIdentifier<VpnPortipToPort> id = buildVpnPortipToPortIdentifier(vpnName, fixedIp);
-            VpnPortipToPortBuilder builder = new VpnPortipToPortBuilder().setKey(
-                    new VpnPortipToPortKey(fixedIp, vpnName)).setVpnName(vpnName).setPortFixedip(fixedIp).setPortName
-                    (portName).setMacAddress(macAddress.toLowerCase()).setSubnetIp(isSubnetIp).setConfig(isConfig)
-                    .setLearnt(isLearnt);
-            MDSALUtil.syncWrite(broker, LogicalDatastoreType.OPERATIONAL, id, builder.build());
-            LOG.debug("ARP learned for fixedIp: {}, vpn {}, interface {}, mac {}, isSubnetIp {} added to " +
-                    "VpnPortipToPort DS", fixedIp, vpnName, portName, macAddress, isLearnt);
+            InstanceIdentifier<LearntVpnVipToPort> id = buildLearntVpnVipToPortIdentifier(vpnName, fixedIp);
+            MDSALUtil.syncDelete(broker, LogicalDatastoreType.OPERATIONAL, id);
+            LOG.debug("removeLearntVpnVipToPort: Delete learned ARP for fixedIp: {}, vpn {} removed from"
+                    + " VpnPortipToPort DS", fixedIp, vpnName);
         }
     }
 
-    protected static void removeVpnPortFixedIpToPort(DataBroker broker, String vpnName, String fixedIp) {
-        synchronized ((vpnName + fixedIp).intern()) {
-            InstanceIdentifier<VpnPortipToPort> id = buildVpnPortipToPortIdentifier(vpnName, fixedIp);
-            MDSALUtil.syncDelete(broker, LogicalDatastoreType.OPERATIONAL, id);
-            LOG.debug("Delete learned ARP for fixedIp: {}, vpn {} removed from VpnPortipToPort DS", fixedIp, vpnName);
-        }
+    static InstanceIdentifier<NetworkMap> buildNetworkMapIdentifier(Uuid networkId) {
+        return InstanceIdentifier.builder(NetworkMaps.class).child(NetworkMap.class, new
+                NetworkMapKey(networkId)).build();
+    }
+
+    static InstanceIdentifier<SubnetOpDataEntry> buildSubnetOpDataEntryInstanceIdentifier(Uuid subnetId) {
+        return InstanceIdentifier.builder(SubnetOpData.class)
+                .child(SubnetOpDataEntry.class, new SubnetOpDataEntryKey(subnetId)).build();
     }
 
     static InstanceIdentifier<VpnPortipToPort> buildVpnPortipToPortIdentifier(String vpnName, String fixedIp) {
-        InstanceIdentifier<VpnPortipToPort> id = InstanceIdentifier.builder(NeutronVpnPortipPortData.class).child
-                (VpnPortipToPort.class, new VpnPortipToPortKey(fixedIp, vpnName)).build();
-        return id;
+        return InstanceIdentifier.builder(NeutronVpnPortipPortData.class).child(VpnPortipToPort.class,
+                new VpnPortipToPortKey(fixedIp, vpnName)).build();
     }
 
-    static VpnPortipToPort getNeutronPortFromVpnPortFixedIp(DataBroker broker, String vpnName, String fixedIp) {
-        InstanceIdentifier id = buildVpnPortipToPortIdentifier(vpnName, fixedIp);
-        Optional<VpnPortipToPort> vpnPortipToPortData = read(broker, LogicalDatastoreType.OPERATIONAL, id);
+    public static VpnPortipToPort getNeutronPortFromVpnPortFixedIp(DataBroker broker, String vpnName, String fixedIp) {
+        InstanceIdentifier<VpnPortipToPort> id = buildVpnPortipToPortIdentifier(vpnName, fixedIp);
+        Optional<VpnPortipToPort> vpnPortipToPortData = read(broker, LogicalDatastoreType.CONFIGURATION, id);
         if (vpnPortipToPortData.isPresent()) {
-            return (vpnPortipToPortData.get());
+            return vpnPortipToPortData.get();
         }
         return null;
     }
 
+    static LearntVpnVipToPort getLearntVpnVipToPort(DataBroker broker, String vpnName, String fixedIp) {
+        InstanceIdentifier<LearntVpnVipToPort> id = buildLearntVpnVipToPortIdentifier(vpnName, fixedIp);
+        Optional<LearntVpnVipToPort> learntVpnVipToPort = read(broker, LogicalDatastoreType.OPERATIONAL, id);
+        if (learntVpnVipToPort.isPresent()) {
+            return learntVpnVipToPort.get();
+        }
+        return null;
+    }
+
+    @Nonnull
     public static List<BigInteger> getDpnsOnVpn(DataBroker dataBroker, String vpnInstanceName) {
-        List<BigInteger> result = new ArrayList<BigInteger>();
+        List<BigInteger> result = new ArrayList<>();
         String rd = getVpnRd(dataBroker, vpnInstanceName);
-        if ( rd == null ) {
-            LOG.debug("Could not find Route-Distinguisher for VpnName={}", vpnInstanceName);
+        if (rd == null) {
+            LOG.debug("getDpnsOnVpn: Could not find Route-Distinguisher for VpnName={}", vpnInstanceName);
             return result;
         }
 
         VpnInstanceOpDataEntry vpnInstanceOpData = getVpnInstanceOpData(dataBroker, rd);
-        if ( vpnInstanceOpData == null ) {
-            LOG.debug("Could not find OpState for VpnName={}", vpnInstanceName);
+        if (vpnInstanceOpData == null) {
+            LOG.debug("getDpnsOnVpn: Could not find OpState for VpnName={}", vpnInstanceName);
             return result;
         }
 
         List<VpnToDpnList> vpnToDpnList = vpnInstanceOpData.getVpnToDpnList();
-        if ( vpnToDpnList == null ) {
-            LOG.debug("Could not find DPN footprint for VpnName={}", vpnInstanceName);
+        if (vpnToDpnList == null) {
+            LOG.debug("getDpnsOnVpn: Could not find DPN footprint for VpnName={}", vpnInstanceName);
             return result;
         }
-        for ( VpnToDpnList vpnToDpn : vpnToDpnList) {
+        for (VpnToDpnList vpnToDpn : vpnToDpnList) {
             result.add(vpnToDpn.getDpnId());
         }
         return result;
@@ -1209,35 +1197,68 @@ public class VpnUtil {
         Optional<Routers> routerData = read(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
         if (routerData.isPresent()) {
             Uuid networkId = routerData.get().getNetworkId();
-            if(networkId != null) {
+            if (networkId != null) {
                 return networkId.getValue();
             }
         }
         return null;
     }
 
+    public static String getAssociatedExternalRouter(DataBroker dataBroker, String extIp) {
+        InstanceIdentifier<ExtRouters> extRouterInstanceIndentifier =
+                InstanceIdentifier.builder(ExtRouters.class).build();
+        Optional<ExtRouters> extRouterData = read(dataBroker, LogicalDatastoreType.CONFIGURATION,
+                extRouterInstanceIndentifier);
+        if (extRouterData.isPresent()) {
+            for (Routers routerData : extRouterData.get().getRouters()) {
+                List<ExternalIps> externalIps = routerData.getExternalIps();
+                for (ExternalIps externalIp : externalIps) {
+                    if (externalIp.getIpAddress().equals(extIp)) {
+                        return routerData.getRouterName();
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
     static InstanceIdentifier<Routers> buildRouterIdentifier(String routerId) {
-        InstanceIdentifier<Routers> routerInstanceIndentifier = InstanceIdentifier.builder(ExtRouters.class).child
-                (Routers.class, new RoutersKey(routerId)).build();
-        return routerInstanceIndentifier;
+        return InstanceIdentifier.builder(ExtRouters.class).child(Routers.class, new RoutersKey(routerId)).build();
     }
 
-    static Uuid getExternalNetworkVpnId(DataBroker dataBroker, Uuid networkId) {
+    static Networks getExternalNetwork(DataBroker dataBroker, Uuid networkId) {
         InstanceIdentifier<Networks> netsIdentifier = InstanceIdentifier.builder(ExternalNetworks.class)
-                .child(Networks.class, new NetworksKey(networkId)).build();
+            .child(Networks.class, new NetworksKey(networkId)).build();
         Optional<Networks> optionalNets = VpnUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION, netsIdentifier);
-        return optionalNets.isPresent() ? optionalNets.get().getVpnid() : null;
+        return optionalNets.isPresent() ? optionalNets.get() : null;
     }
 
-    static Optional<List<String>> getAllSubnetGatewayMacAddressesforVpn(DataBroker broker, String vpnName) {
-        Optional<List<String>> macAddressesOptional = Optional.absent();
+    static Uuid getExternalNetworkVpnId(DataBroker dataBroker, Uuid networkId) {
+        Networks extNetwork = getExternalNetwork(dataBroker, networkId);
+        return extNetwork != null ? extNetwork.getVpnid() : null;
+    }
+
+    static List<Uuid> getExternalNetworkRouterIds(DataBroker dataBroker, Uuid networkId) {
+        Networks extNetwork = getExternalNetwork(dataBroker, networkId);
+        return extNetwork != null ? extNetwork.getRouterIds() : Collections.emptyList();
+    }
+
+    static Routers getExternalRouter(DataBroker dataBroker, String routerId) {
+        InstanceIdentifier<Routers> id = InstanceIdentifier.builder(ExtRouters.class)
+                .child(Routers.class, new RoutersKey(routerId)).build();
+        Optional<Routers> routerData = read(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
+        return routerData.isPresent() ? routerData.get() : null;
+    }
+
+    static List<String> getAllSubnetGatewayMacAddressesforVpn(DataBroker broker, String vpnName) {
         List<String> macAddresses = new ArrayList<>();
-        Optional<Subnetmaps> subnetMapsData = read(broker, LogicalDatastoreType.CONFIGURATION, buildSubnetMapsWildCardPath());
+        Optional<Subnetmaps> subnetMapsData =
+            read(broker, LogicalDatastoreType.CONFIGURATION, buildSubnetMapsWildCardPath());
         if (subnetMapsData.isPresent()) {
             List<Subnetmap> subnetMapList = subnetMapsData.get().getSubnetmap();
             if (subnetMapList != null && !subnetMapList.isEmpty()) {
-                for (Subnetmap subnet: subnetMapList) {
-                    if (subnet.getVpnId() !=null && subnet.getVpnId().equals(Uuid.getDefaultInstance(vpnName))) {
+                for (Subnetmap subnet : subnetMapList) {
+                    if (subnet.getVpnId() != null && subnet.getVpnId().equals(Uuid.getDefaultInstance(vpnName))) {
                         String routerIntfMacAddress = subnet.getRouterIntfMacAddress();
                         if (routerIntfMacAddress != null && !routerIntfMacAddress.isEmpty()) {
                             macAddresses.add(subnet.getRouterIntfMacAddress());
@@ -1245,154 +1266,695 @@ public class VpnUtil {
                     }
                 }
             }
-            if (!macAddresses.isEmpty()) {
-                return Optional.of(macAddresses);
-            }
         }
-        return macAddressesOptional;
+        return macAddresses;
     }
 
     static InstanceIdentifier<Subnetmaps> buildSubnetMapsWildCardPath() {
         return InstanceIdentifier.create(Subnetmaps.class);
     }
 
-    static void setupSubnetMacIntoVpnInstance(DataBroker dataBroker, IMdsalApiManager mdsalManager,
-            String vpnName, String srcMacAddress, BigInteger dpnId, WriteTransaction writeTx, int addOrRemove) {
-        long vpnId = getVpnId(dataBroker, vpnName);
-        if (dpnId.equals(BigInteger.ZERO)) {
-            /* Apply the MAC on all DPNs in a VPN */
-            List<BigInteger> dpIds = getDpnsOnVpn(dataBroker, vpnName);
-            if (dpIds == null || dpIds.isEmpty()) {
-                return;
-            }
-            for (BigInteger dpId : dpIds) {
-                addGwMacIntoTx(mdsalManager, srcMacAddress, writeTx, addOrRemove, vpnId, dpId);
-            }
-        } else {
-            addGwMacIntoTx(mdsalManager, srcMacAddress, writeTx, addOrRemove, vpnId, dpnId);
+    public static FlowEntity buildL3vpnGatewayFlow(BigInteger dpId, String gwMacAddress, long vpnId,
+            long subnetVpnId) {
+        List<MatchInfo> mkMatches = new ArrayList<>();
+        mkMatches.add(new MatchMetadata(MetaDataUtil.getVpnIdMetadata(vpnId), MetaDataUtil.METADATA_MASK_VRFID));
+        mkMatches.add(new MatchEthernetDestination(new MacAddress(gwMacAddress)));
+        List<InstructionInfo> mkInstructions = new ArrayList<>();
+        mkInstructions.add(new InstructionGotoTable(NwConstants.L3_FIB_TABLE));
+        if (subnetVpnId != VpnConstants.INVALID_ID) {
+            BigInteger subnetIdMetaData = MetaDataUtil.getVpnIdMetadata(subnetVpnId);
+            mkInstructions.add(new InstructionWriteMetadata(subnetIdMetaData, MetaDataUtil.METADATA_MASK_VRFID));
         }
-    }
 
-    static void addGwMacIntoTx(IMdsalApiManager mdsalManager, String srcMacAddress, WriteTransaction writeTx,
-            int addOrRemove, long vpnId, BigInteger dpId) {
-        FlowEntity flowEntity = buildL3vpnGatewayFlow(dpId, srcMacAddress, vpnId);
-        if (addOrRemove == NwConstants.ADD_FLOW) {
-            mdsalManager.addFlowToTx(flowEntity, writeTx);
-        } else {
-            mdsalManager.removeFlowToTx(flowEntity, writeTx);
-        }
-    }
-
-    public static FlowEntity buildL3vpnGatewayFlow(BigInteger dpId, String gwMacAddress, long vpnId) {
-        List<MatchInfo> mkMatches = new ArrayList<MatchInfo>();
-        mkMatches.add(new MatchInfo(MatchFieldType.metadata, new BigInteger[] {
-                MetaDataUtil.getVpnIdMetadata(vpnId), MetaDataUtil.METADATA_MASK_VRFID }));
-        mkMatches.add(new MatchInfo(MatchFieldType.eth_dst, new String[] { gwMacAddress }));
-        List<InstructionInfo> mkInstructions = new ArrayList<InstructionInfo>();
-        mkInstructions.add(new InstructionInfo(InstructionType.goto_table, new long[] { NwConstants.L3_FIB_TABLE }));
         String flowId = getL3VpnGatewayFlowRef(NwConstants.L3_GW_MAC_TABLE, dpId, vpnId, gwMacAddress);
-        FlowEntity flowEntity = MDSALUtil.buildFlowEntity(dpId, NwConstants.L3_GW_MAC_TABLE,
+
+        return MDSALUtil.buildFlowEntity(dpId, NwConstants.L3_GW_MAC_TABLE,
                 flowId, 20, flowId, 0, 0, NwConstants.COOKIE_L3_GW_MAC_TABLE, mkMatches, mkInstructions);
-        return flowEntity;
     }
 
     private static String getL3VpnGatewayFlowRef(short l3GwMacTable, BigInteger dpId, long vpnId, String gwMacAddress) {
-        return gwMacAddress+NwConstants.FLOWID_SEPARATOR+vpnId+NwConstants.FLOWID_SEPARATOR+dpId+NwConstants.FLOWID_SEPARATOR+l3GwMacTable;
-    }
-
-    //TODO: How to handle the below code, its a copy paste from MDSALManager.java
-    public static Node buildDpnNode(BigInteger dpnId) {
-        NodeId nodeId = new NodeId("openflow:" + dpnId);
-        Node nodeDpn = new NodeBuilder().setId(nodeId).setKey(new NodeKey(nodeId)).build();
-
-        return nodeDpn;
+        return gwMacAddress + NwConstants.FLOWID_SEPARATOR + vpnId + NwConstants.FLOWID_SEPARATOR + dpId
+            + NwConstants.FLOWID_SEPARATOR + l3GwMacTable;
     }
 
     public static void lockSubnet(LockManagerService lockManager, String subnetId) {
-        TryLockInput input = new TryLockInputBuilder().setLockName(subnetId).setTime(3000L).setTimeUnit(TimeUnits.Milliseconds).build();
+        TryLockInput input =
+            new TryLockInputBuilder().setLockName(subnetId).setTime(3000L).setTimeUnit(TimeUnits.Milliseconds).build();
         Future<RpcResult<Void>> result = lockManager.tryLock(input);
         String errMsg = "Unable to getLock for subnet " + subnetId;
         try {
-            if ((result != null) && (result.get().isSuccessful())) {
-                    LOG.debug("Acquired lock for {}", subnetId);
+            if (result != null && result.get().isSuccessful()) {
+                LOG.debug("lockSubnet: Acquired lock for {}", subnetId);
             } else {
                 throw new RuntimeException(errMsg);
             }
         } catch (InterruptedException | ExecutionException e) {
             LOG.error(errMsg);
-            throw new RuntimeException(errMsg, e.getCause());
+            throw new RuntimeException(e.getMessage(), e);
         }
     }
 
+    // We store the cause, which is what we really care about
+    @SuppressWarnings("checkstyle:AvoidHidingCauseException")
     public static void unlockSubnet(LockManagerService lockManager, String subnetId) {
         UnlockInput input = new UnlockInputBuilder().setLockName(subnetId).build();
         Future<RpcResult<Void>> result = lockManager.unlock(input);
         try {
-            if ((result != null) && (result.get().isSuccessful())) {
-                LOG.debug("Unlocked {}", subnetId);
+            if (result != null && result.get().isSuccessful()) {
+                LOG.debug("unlockSubnet: Unlocked {}", subnetId);
             } else {
-                LOG.debug("Unable to unlock subnet {}", subnetId);
+                LOG.debug("unlockSubnet: Unable to unlock subnet {}", subnetId);
             }
         } catch (InterruptedException | ExecutionException e) {
-            LOG.error("Unable to unlock subnet {}", subnetId);
+            LOG.error("unlockSubnet: Unable to unlock subnet {}", subnetId);
             throw new RuntimeException(String.format("Unable to unlock subnetId %s", subnetId), e.getCause());
         }
     }
 
     static Optional<IpAddress> getGatewayIpAddressFromInterface(String srcInterface,
             INeutronVpnManager neutronVpnService, DataBroker dataBroker) {
-        Optional <IpAddress> gatewayIp = Optional.absent();
-        Port port = neutronVpnService.getNeutronPort(srcInterface);
-        //TODO(Gobinath): Need to fix this as assuming port will belong to only one Subnet would be incorrect"
-        gatewayIp = Optional.of(neutronVpnService.getNeutronSubnet(port.getFixedIps().get(0).getSubnetId()).getGatewayIp());
+        Optional<IpAddress> gatewayIp = Optional.absent();
+        if (neutronVpnService != null) {
+            //TODO(Gobinath): Need to fix this as assuming port will belong to only one Subnet would be incorrect"
+            Port port = neutronVpnService.getNeutronPort(srcInterface);
+            if (port != null && port.getFixedIps() != null && port.getFixedIps().get(0) != null
+                && port.getFixedIps().get(0).getSubnetId() != null) {
+                gatewayIp = Optional.of(
+                    neutronVpnService.getNeutronSubnet(port.getFixedIps().get(0).getSubnetId()).getGatewayIp());
+            }
+        } else {
+            LOG.error("getGatewayIpAddressFromInterface: neutron vpn service is not configured."
+                    + " Failed for interface {}.", srcInterface);
+        }
         return gatewayIp;
     }
 
     static Optional<String> getGWMacAddressFromInterface(MacEntry macEntry, IpAddress gatewayIp,
-            DataBroker dataBroker, OdlInterfaceRpcService interfaceRpc) {
-        Optional <String> gatewayMac = Optional.absent();
+        DataBroker dataBroker, OdlInterfaceRpcService interfaceRpc) {
+        Optional<String> gatewayMac = Optional.absent();
         long vpnId = getVpnId(dataBroker, macEntry.getVpnName());
-        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds>
-        vpnIdsInstanceIdentifier = VpnUtil.getVpnIdToVpnInstanceIdentifier(vpnId);
-        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds> vpnIdsOptional
-        = VpnUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION, vpnIdsInstanceIdentifier);
+        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn
+            .instance.VpnIds>
+            vpnIdsInstanceIdentifier = VpnUtil.getVpnIdToVpnInstanceIdentifier(vpnId);
+        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds>
+            vpnIdsOptional
+            = VpnUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION, vpnIdsInstanceIdentifier);
         if (!vpnIdsOptional.isPresent()) {
-            LOG.trace("VPN {} not configured", vpnId);
+            LOG.error("getGWMacAddressFromInterface: VPN {} not configured", vpnId);
             return gatewayMac;
         }
         VpnPortipToPort vpnTargetIpToPort = VpnUtil.getNeutronPortFromVpnPortFixedIp(dataBroker,
-                macEntry.getVpnName(), gatewayIp.getIpv4Address().getValue());
+            macEntry.getVpnName(), gatewayIp.getIpv4Address().getValue());
         if (vpnTargetIpToPort != null && vpnTargetIpToPort.isSubnetIp()) {
             gatewayMac = Optional.of(vpnTargetIpToPort.getMacAddress());
         } else {
-            org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds vpnIds = vpnIdsOptional.get();
-            if(vpnIds.isExternalVpn()) {
+            org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds vpnIds =
+                vpnIdsOptional.get();
+            if (vpnIds.isExternalVpn()) {
                 gatewayMac = InterfaceUtils.getMacAddressForInterface(dataBroker, macEntry.getInterfaceName());
             }
         }
         return gatewayMac;
-
     }
 
-    public static boolean isVpnIntfPresentInVpnToDpnList(DataBroker broker, VpnInterface vpnInterface) {
+    public static boolean isVpnIntfPresentInVpnToDpnList(DataBroker broker,
+                                                      VpnInterface vpnInterface, String vpnName) {
         BigInteger dpnId = vpnInterface.getDpnId();
-        String rd = VpnUtil.getVpnRd(broker, vpnInterface.getVpnInstanceName());
+        String rd = VpnUtil.getVpnRd(broker, vpnName);
+        LOG.trace("isVpnIntfPresentInVpnToDpnList: GOT rd {} for VpnInterface {}  VpnInstance {} ", rd ,
+                 vpnInterface.getName(), vpnName);
         VpnInstanceOpDataEntry vpnInstanceOpData = VpnUtil.getVpnInstanceOpDataFromCache(broker, rd);
         if (vpnInstanceOpData != null) {
+            LOG.trace("isVpnIntfPresentInVpnToDpnList: GOT VpnInstanceOp {} for rd {} ", vpnInstanceOpData, rd);
             List<VpnToDpnList> dpnToVpns = vpnInstanceOpData.getVpnToDpnList();
-            if (dpnToVpns!= null) {
-                for (VpnToDpnList dpn :dpnToVpns) {
+            if (dpnToVpns != null) {
+                for (VpnToDpnList dpn : dpnToVpns) {
                     if (dpn.getDpnId().equals(dpnId)) {
-                        if (dpn.getVpnInterfaces().contains(vpnInterface.getName())) {
-                            return true;
-                        } else {
-                            return false;
-                        }
+                        return dpn.getVpnInterfaces().stream().anyMatch(
+                            vpnInterfaces -> vpnInterface.getName().equals(vpnInterfaces.getInterfaceName()));
                     }
+                    LOG.info("isVpnIntfPresentInVpnToDpnList: VpnInterface {} not present in DpnId {} vpn {}",
+                            vpnInterface.getName(), dpn.getDpnId(), vpnName);
+                }
+            }
+        }
+        return false;
+    }
+
+    public static void setupGwMacIfExternalVpn(DataBroker dataBroker, IMdsalApiManager mdsalManager, BigInteger dpnId,
+            String interfaceName, long vpnId, WriteTransaction writeInvTxn, int addOrRemove, String gwMac) {
+        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance
+            .VpnIds> vpnIdsInstanceIdentifier = getVpnIdToVpnInstanceIdentifier(vpnId);
+        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance
+            .VpnIds> vpnIdsOptional = read(
+                dataBroker, LogicalDatastoreType.CONFIGURATION, vpnIdsInstanceIdentifier);
+        if (vpnIdsOptional.isPresent() && vpnIdsOptional.get().isExternalVpn()) {
+            if (gwMac == null) {
+                LOG.error("setupGwMacIfExternalVpn: Failed to get gwMacAddress for interface {} on dpn {} vpn {}",
+                        interfaceName, dpnId.toString(), vpnIdsOptional.get().getVpnInstanceName());
+                return;
+            }
+            FlowEntity flowEntity = VpnUtil.buildL3vpnGatewayFlow(dpnId, gwMac, vpnId, VpnConstants.INVALID_ID);
+            if (addOrRemove == NwConstants.ADD_FLOW) {
+                mdsalManager.addFlowToTx(flowEntity, writeInvTxn);
+            } else if (addOrRemove == NwConstants.DEL_FLOW) {
+                mdsalManager.removeFlowToTx(flowEntity, writeInvTxn);
+            }
+        }
+    }
+
+    public static Optional<VpnPortipToPort> getRouterInterfaceForVpnInterface(DataBroker dataBroker,
+                                                                              String interfaceName,
+                                                                              String vpnName,
+                                                                              Uuid subnetUuid) {
+        Optional<VpnPortipToPort> gwPortOptional = Optional.absent();
+        if (subnetUuid != null) {
+            final Optional<String> gatewayIp = getVpnSubnetGatewayIp(dataBroker, subnetUuid);
+            if (gatewayIp.isPresent()) {
+                String gwIp = gatewayIp.get();
+                gwPortOptional = Optional.fromNullable(getNeutronPortFromVpnPortFixedIp(dataBroker, vpnName, gwIp));
+            }
+        }
+        return gwPortOptional;
+    }
+
+    public static Optional<String> getVpnSubnetGatewayIp(DataBroker dataBroker, final Uuid subnetUuid) {
+        Optional<String> gwIpAddress = Optional.absent();
+        final SubnetKey subnetkey = new SubnetKey(subnetUuid);
+        final InstanceIdentifier<Subnet> subnetidentifier = InstanceIdentifier.create(Neutron.class)
+                .child(Subnets.class)
+                .child(Subnet.class, subnetkey);
+        final Optional<Subnet> subnet = read(dataBroker, LogicalDatastoreType.CONFIGURATION, subnetidentifier);
+        if (subnet.isPresent()) {
+            Class<? extends IpVersionBase> ipVersionBase = subnet.get().getIpVersion();
+            if (ipVersionBase.equals(IpVersionV4.class)) {
+                LOG.trace("getVpnSubnetGatewayIp: Obtained subnet {} for vpn interface",
+                        subnet.get().getUuid().getValue());
+                gwIpAddress = Optional.of(subnet.get().getGatewayIp().getIpv4Address().getValue());
+                return gwIpAddress;
+            }
+        }
+        return gwIpAddress;
+    }
+
+    public static RouterToNaptSwitch getRouterToNaptSwitch(DataBroker dataBroker, String routerName) {
+        InstanceIdentifier<RouterToNaptSwitch> id = InstanceIdentifier.builder(NaptSwitches.class)
+                .child(RouterToNaptSwitch.class, new RouterToNaptSwitchKey(routerName)).build();
+        Optional<RouterToNaptSwitch> routerToNaptSwitchData = read(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
+        return routerToNaptSwitchData.isPresent() ? routerToNaptSwitchData.get() : null;
+    }
+
+    static InstanceIdentifier<Subnetmap> buildSubnetmapIdentifier(Uuid subnetId) {
+        return InstanceIdentifier.builder(Subnetmaps.class)
+        .child(Subnetmap.class, new SubnetmapKey(subnetId)).build();
+
+    }
+
+    public static BigInteger getPrimarySwitchForRouter(DataBroker dataBroker, String routerName) {
+        RouterToNaptSwitch routerToNaptSwitch = getRouterToNaptSwitch(dataBroker, routerName);
+        return routerToNaptSwitch != null ? routerToNaptSwitch.getPrimarySwitchId() : null;
+    }
+
+    static boolean isL3VpnOverVxLan(Long l3Vni) {
+        return l3Vni != null && l3Vni != 0;
+    }
+
+    static boolean isEvpnOverVxLan(Long l2Vni) { //To be used by RT2
+        return l2Vni != null && l2Vni != 0;
+    }
+
+    /**
+     * Retrieves the primary rd of a vpn instance
+     * Primary rd will be the first rd in the list of rds configured for a vpn instance
+     * If rd list is empty, primary rd will be vpn instance name
+     * Use this function only during create operation cycles. For other operations, use getVpnRd() method.
+     *
+     * @param dataBroker dataBroker service reference
+     * @param vpnName Name of the VPN
+     * @return the primary rd of the VPN
+     */
+    public static String getPrimaryRd(DataBroker dataBroker, String vpnName) {
+        // Retrieves the VPN Route Distinguisher by its Vpn instance name
+        String rd = getVpnRd(dataBroker, vpnName);
+        if (rd != null) {
+            return rd;
+        }
+        InstanceIdentifier<VpnInstance> id  = getVpnInstanceIdentifier(vpnName);
+        Optional<VpnInstance> vpnInstance = VpnUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
+        if (vpnInstance.isPresent()) {
+            return getPrimaryRd(vpnInstance.get());
+        }
+        return vpnName;
+    }
+
+    /**
+     * Retrieves the primary rd of a vpn instance
+     * Primary rd will be the first rd in the list of rds configured for a vpn instance
+     * If rd list is empty, primary rd will be vpn instance name
+     * Use this function only during create operation cycles. For other operations, use getVpnRd() method.
+     *
+     * @param vpnInstance Config Vpn Instance Object
+     * @return the primary rd of the VPN
+     */
+    public static String getPrimaryRd(VpnInstance vpnInstance) {
+        List<String> rds = null;
+        if (vpnInstance != null) {
+            rds = getListOfRdsFromVpnInstance(vpnInstance);
+        }
+        return rds == null || rds.isEmpty() ? vpnInstance.getVpnInstanceName() : rds.get(0);
+    }
+
+    public static boolean isBgpVpn(String vpnName, String primaryRd) {
+        return !vpnName.equals(primaryRd);
+    }
+
+    static java.util.Optional<String> allocateRdForExtraRouteAndUpdateUsedRdsMap(
+            DataBroker dataBroker, long vpnId, @Nullable Long parentVpnId, String prefix, String vpnName,
+            String nextHop, BigInteger dpnId, WriteTransaction writeOperTxn) {
+        //Check if rd is already allocated for this extraroute behind the same VM. If yes, reuse it.
+        //This is particularly useful during reboot scenarios.
+        java.util.Optional<String> allocatedRd = VpnExtraRouteHelper
+                .getRdAllocatedForExtraRoute(dataBroker, vpnId, prefix, nextHop);
+        if (allocatedRd.isPresent()) {
+            return java.util.Optional.of(allocatedRd.get());
+        }
+
+        //Check if rd is already allocated for this extraroute behind the same CSS. If yes, reuse it
+        List<String> usedRds = VpnExtraRouteHelper.getUsedRds(dataBroker, vpnId, prefix);
+        for (String usedRd : usedRds) {
+            Optional<Routes> vpnExtraRoutes = VpnExtraRouteHelper.getVpnExtraroutes(dataBroker,
+                    vpnName, usedRd, prefix);
+            if (vpnExtraRoutes.isPresent()) {
+                String nextHopIp = vpnExtraRoutes.get().getNexthopIpList().get(0);
+                // In case of VPN importing the routes, the interface is not present in the VPN
+                // and has to be fetched from the VPN from which it imports
+                Optional<Prefixes> prefixToInterface =
+                        getPrefixToInterface(dataBroker, parentVpnId != null ? parentVpnId : vpnId, nextHopIp);
+                if (prefixToInterface.isPresent() && dpnId.equals(prefixToInterface.get().getDpnId())) {
+                    syncUpdate(dataBroker, LogicalDatastoreType.CONFIGURATION,
+                            VpnExtraRouteHelper.getUsedRdsIdentifier(vpnId, prefix, nextHop),
+                            getRdsBuilder(nextHop, usedRd).build());
+                    return java.util.Optional.of(usedRd);
+                }
+            }
+        }
+        List<String> availableRds = getVpnRdsFromVpnInstanceConfig(dataBroker, vpnName);
+        String rd;
+        if (availableRds.isEmpty()) {
+            rd = dpnId.toString();
+            LOG.debug("Internal vpn {} Returning DpnId {} as rd", vpnName, rd);
+        } else {
+            LOG.trace(
+                    "Removing used rds {} from available rds {} vpnid {} . prefix is {} , vpname- {}, dpnId- {},"
+                    + " adj - {}", usedRds, availableRds, vpnId, prefix, vpnName, dpnId);
+            availableRds.removeAll(usedRds);
+            if (availableRds.isEmpty()) {
+                LOG.error("No rd available from VpnInstance to allocate for prefix {}", prefix);
+                return java.util.Optional.empty();
+            }
+            // If rd is not allocated for this prefix or if extra route is behind different OVS, select a new rd.
+            rd = availableRds.get(0);
+        }
+        syncUpdate(dataBroker, LogicalDatastoreType.CONFIGURATION,
+                VpnExtraRouteHelper.getUsedRdsIdentifier(vpnId, prefix, nextHop),
+                getRdsBuilder(nextHop, rd).build());
+        return java.util.Optional.ofNullable(rd);
+    }
+
+    static String getVpnNamePrefixKey(String vpnName, String prefix) {
+        return vpnName + VpnConstants.SEPARATOR + prefix;
+    }
+
+    static InstanceIdentifier<Adjacency> getAdjacencyIdentifier(String vpnInterfaceName, String ipAddress) {
+        return InstanceIdentifier.builder(VpnInterfaces.class)
+                .child(VpnInterface.class, new VpnInterfaceKey(vpnInterfaceName))
+                .augmentation(Adjacencies.class).child(Adjacency.class, new AdjacencyKey(ipAddress)).build();
+    }
+
+    public static List<String> getIpsListFromExternalIps(List<ExternalIps> externalIps) {
+        if (externalIps == null) {
+            return Collections.emptyList();
+        }
+
+        return externalIps.stream().map(ExternalIps::getIpAddress).collect(Collectors.toList());
+    }
+
+    static void bindService(final String vpnInstanceName, final String interfaceName, DataBroker dataBroker,
+                            boolean isTunnelInterface, JobCoordinator jobCoordinator) {
+        jobCoordinator.enqueueJob(interfaceName,
+            () -> {
+                WriteTransaction writeTxn = dataBroker.newWriteOnlyTransaction();
+                BoundServices serviceInfo = isTunnelInterface
+                        ? VpnUtil.getBoundServicesForTunnelInterface(vpnInstanceName, interfaceName)
+                        : getBoundServicesForVpnInterface(dataBroker, vpnInstanceName, interfaceName);
+                writeTxn.put(LogicalDatastoreType.CONFIGURATION, InterfaceUtils.buildServiceId(interfaceName,
+                        ServiceIndex.getIndex(NwConstants.L3VPN_SERVICE_NAME, NwConstants.L3VPN_SERVICE_INDEX)),
+                        serviceInfo, WriteTransaction.CREATE_MISSING_PARENTS);
+                return Collections.singletonList(writeTxn.submit());
+            });
+    }
+
+    static BoundServices getBoundServicesForVpnInterface(DataBroker broker, String vpnName, String interfaceName) {
+        List<Instruction> instructions = new ArrayList<>();
+        int instructionKey = 0;
+        final long vpnId = VpnUtil.getVpnId(broker, vpnName);
+        List<Action> actions = Collections.singletonList(
+                new ActionRegLoad(0, VpnConstants.VPN_REG_ID, 0, VpnConstants.VPN_ID_LENGTH, vpnId).buildAction());
+        instructions.add(MDSALUtil.buildApplyActionsInstruction(actions, ++instructionKey));
+        instructions.add(
+                MDSALUtil.buildAndGetWriteMetadaInstruction(MetaDataUtil.getVpnIdMetadata(vpnId),
+                        MetaDataUtil.METADATA_MASK_VRFID, ++instructionKey));
+        instructions.add(MDSALUtil.buildAndGetGotoTableInstruction(NwConstants.L3_GW_MAC_TABLE,
+                ++instructionKey));
+        BoundServices serviceInfo = InterfaceUtils.getBoundServices(
+                String.format("%s.%s.%s", "vpn", vpnName, interfaceName),
+                ServiceIndex.getIndex(NwConstants.L3VPN_SERVICE_NAME, NwConstants.L3VPN_SERVICE_INDEX),
+                VpnConstants.DEFAULT_FLOW_PRIORITY, NwConstants.COOKIE_VM_INGRESS_TABLE, instructions);
+        return serviceInfo;
+    }
+
+    static BoundServices getBoundServicesForTunnelInterface(String vpnName, String interfaceName) {
+        int instructionKey = 0;
+        List<Instruction> instructions = new ArrayList<>();
+        instructions.add(MDSALUtil.buildAndGetGotoTableInstruction(
+                NwConstants.L3VNI_EXTERNAL_TUNNEL_DEMUX_TABLE, ++instructionKey));
+        BoundServices serviceInfo = InterfaceUtils.getBoundServices(String.format("%s.%s.%s", "vpn",
+                vpnName, interfaceName),
+                ServiceIndex.getIndex(NwConstants.L3VPN_SERVICE_NAME,
+                        NwConstants.L3VNI_EXTERNAL_TUNNEL_DEMUX_TABLE), VpnConstants.DEFAULT_FLOW_PRIORITY,
+                NwConstants.COOKIE_VM_INGRESS_TABLE, instructions);
+        return serviceInfo;
+    }
+
+    static void unbindService(DataBroker dataBroker, final String vpnInterfaceName, boolean isInterfaceStateDown,
+            JobCoordinator jobCoordinator) {
+        if (!isInterfaceStateDown) {
+            jobCoordinator.enqueueJob(vpnInterfaceName,
+                () -> {
+                    WriteTransaction writeTxn = dataBroker.newWriteOnlyTransaction();
+                    writeTxn.delete(LogicalDatastoreType.CONFIGURATION,
+                            InterfaceUtils.buildServiceId(vpnInterfaceName,
+                                    ServiceIndex.getIndex(NwConstants.L3VPN_SERVICE_NAME,
+                                            NwConstants.L3VPN_SERVICE_INDEX)));
+
+                    List<ListenableFuture<Void>> futures = new ArrayList<>();
+                    futures.add(writeTxn.submit());
+                    return futures;
+                });
+        }
+    }
+
+    static FlowEntity buildFlowEntity(BigInteger dpnId, short tableId, String flowId) {
+        return new FlowEntityBuilder()
+            .setDpnId(dpnId)
+            .setTableId(tableId)
+            .setFlowId(flowId)
+            .build();
+    }
+
+    static VrfEntryBase.EncapType getEncapType(boolean isVxLan) {
+        return isVxLan ? VrfEntryBase.EncapType.Vxlan : VrfEntryBase.EncapType.Mplsgre;
+    }
+
+    static org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.subnets
+        .Subnets getExternalSubnet(DataBroker dataBroker, Uuid subnetId) {
+        InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.subnets
+            .Subnets> subnetsIdentifier = InstanceIdentifier.builder(ExternalSubnets.class)
+                .child(org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.subnets
+                        .Subnets.class, new SubnetsKey(subnetId)).build();
+        Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external.subnets.Subnets>
+            optionalSubnets = VpnUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION, subnetsIdentifier);
+        return optionalSubnets.isPresent() ? optionalSubnets.get() : null;
+    }
+
+    static Uuid getSubnetFromExternalRouterByIp(DataBroker dataBroker, Uuid routerId, String ip) {
+        Routers externalRouter = VpnUtil.getExternalRouter(dataBroker, routerId.getValue());
+        if (externalRouter != null && externalRouter.getExternalIps() != null) {
+            for (ExternalIps externalIp : externalRouter.getExternalIps()) {
+                if (externalIp.getIpAddress().equals(ip)) {
+                    return externalIp.getSubnetId();
                 }
             }
         }
+        return null;
+    }
+
+    static boolean isExternalSubnetVpn(String vpnName, String subnetId) {
+        return vpnName.equals(subnetId);
+    }
+
+    static Boolean getIsExternal(Network network) {
+        return network.getAugmentation(NetworkL3Extension.class) != null
+                && network.getAugmentation(NetworkL3Extension.class).isExternal();
+    }
+
+    @SuppressWarnings("checkstyle:linelength")
+    static Network getNeutronNetwork(DataBroker broker, Uuid networkId) {
+        Network network = null;
+        LOG.debug("getNeutronNetwork for {}", networkId.getValue());
+        InstanceIdentifier<Network> inst = InstanceIdentifier.create(Neutron.class).child(
+                org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.networks.rev150712.networks.attributes.Networks.class).child(
+                Network.class, new NetworkKey(networkId));
+        Optional<Network> net = read(broker, LogicalDatastoreType.CONFIGURATION, inst);
+        if (net.isPresent()) {
+            network = net.get();
+        }
+        return network;
+    }
+
+    public static boolean isEligibleForBgp(String rd, String vpnName, BigInteger dpnId, String networkName) {
+        if (rd != null) {
+            if (vpnName != null && rd.equals(vpnName)) {
+                return false;
+            }
+            if (dpnId != null && rd.equals(dpnId.toString())) {
+                return false;
+            }
+            if (networkName != null && rd.equals(networkName)) {
+                return false;
+            }
+            return true;
+        }
         return false;
     }
 
+    static String getFibFlowRef(BigInteger dpnId, short tableId, String vpnName, int priority) {
+        return VpnConstants.FLOWID_PREFIX + dpnId + NwConstants.FLOWID_SEPARATOR + tableId
+                + NwConstants.FLOWID_SEPARATOR + vpnName + NwConstants.FLOWID_SEPARATOR + priority;
+    }
+
+    static void removeExternalTunnelDemuxFlows(String vpnName, DataBroker broker, IMdsalApiManager mdsalManager) {
+        LOG.info("Removing external tunnel flows for vpn {}", vpnName);
+        for (BigInteger dpnId: NWUtil.getOperativeDPNs(broker)) {
+            LOG.debug("Removing external tunnel flows for vpn {} from dpn {}", vpnName, dpnId);
+            String flowRef = getFibFlowRef(dpnId, NwConstants.L3VNI_EXTERNAL_TUNNEL_DEMUX_TABLE,
+                    vpnName, VpnConstants.DEFAULT_FLOW_PRIORITY);
+            FlowEntity flowEntity = VpnUtil.buildFlowEntity(dpnId,
+                    NwConstants.L3VNI_EXTERNAL_TUNNEL_DEMUX_TABLE, flowRef);
+            mdsalManager.removeFlow(flowEntity);
+        }
+    }
+
+    public static boolean isVpnPendingDelete(DataBroker broker, String rd) {
+        VpnInstanceOpDataEntry vpnInstanceOpData = getVpnInstanceOpData(broker, rd);
+        boolean isVpnPendingDelete = false;
+        if (vpnInstanceOpData == null
+                || vpnInstanceOpData.getVpnState() == VpnInstanceOpDataEntry.VpnState.PendingDelete) {
+            isVpnPendingDelete = true;
+        }
+        return isVpnPendingDelete;
+    }
+
+    public static List<VpnInstanceOpDataEntry> getVpnsImportingMyRoute(final DataBroker broker, final String vpnName) {
+        List<VpnInstanceOpDataEntry> vpnsToImportRoute = new ArrayList<>();
+
+        final String vpnRd = getVpnRd(broker, vpnName);
+        if (vpnRd == null) {
+            LOG.error("getVpnsImportingMyRoute: vpn {} not present in config DS.", vpnName);
+            return vpnsToImportRoute;
+        }
+        final VpnInstanceOpDataEntry vpnInstanceOpDataEntry = VpnUtil.getVpnInstanceOpData(broker, vpnRd);
+        if (vpnInstanceOpDataEntry == null) {
+            LOG.error("getVpnsImportingMyRoute: Could not retrieve vpn instance op data for {}"
+                    + " to check for vpns importing the routes", vpnName);
+            return vpnsToImportRoute;
+        }
+
+        Predicate<VpnInstanceOpDataEntry> excludeVpn = input -> {
+            if (input.getVpnInstanceName() == null) {
+                LOG.error("getVpnsImportingMyRoute.excludeVpn: Received vpn instance with rd {} without a name.",
+                        input.getVrfId());
+                return false;
+            }
+            return !input.getVpnInstanceName().equals(vpnName);
+        };
+
+        Predicate<VpnInstanceOpDataEntry> matchRTs = input -> {
+            Iterable<String> commonRTs =
+                intersection(getRts(vpnInstanceOpDataEntry, VpnTarget.VrfRTType.ExportExtcommunity),
+                    getRts(input, VpnTarget.VrfRTType.ImportExtcommunity));
+            return Iterators.size(commonRTs.iterator()) > 0;
+        };
+
+        vpnsToImportRoute = getAllVpnInstanceOpData(broker)
+                .stream()
+                .filter(excludeVpn)
+                .filter(matchRTs)
+                .collect(Collectors.toList());
+        return vpnsToImportRoute;
+    }
+
+    public static List<String> getRts(VpnInstanceOpDataEntry vpnInstance, VpnTarget.VrfRTType rtType) {
+        String name = vpnInstance.getVpnInstanceName();
+        List<String> rts = new ArrayList<>();
+        VpnTargets targets = vpnInstance.getVpnTargets();
+        if (targets == null) {
+            LOG.info("getRts: vpn targets not available for {}", name);
+            return rts;
+        }
+        List<VpnTarget> vpnTargets = targets.getVpnTarget();
+        if (vpnTargets == null) {
+            LOG.info("getRts: vpnTarget values not available for {}", name);
+            return rts;
+        }
+        for (VpnTarget target : vpnTargets) {
+            //TODO: Check for RT type is Both
+            if (target.getVrfRTType().equals(rtType) || target.getVrfRTType().equals(VpnTarget.VrfRTType.Both)) {
+                String rtValue = target.getVrfRTValue();
+                rts.add(rtValue);
+            }
+        }
+        return rts;
+    }
+
+    public static <T> Iterable<T> intersection(final Collection<T> collection1, final Collection<T> collection2) {
+        Set<T> intersection = new HashSet<>(collection1);
+        intersection.retainAll(collection2);
+        return intersection;
+    }
+
+    /** Get Subnetmap from its Uuid.
+     * @param broker the data broker for look for data
+     * @param subnetUuid the subnet's Uuid
+     * @return the Subnetmap of Uuid or null if it is not found
+     */
+    public static Subnetmap getSubnetmapFromItsUuid(DataBroker broker, Uuid subnetUuid) {
+        Subnetmap sn = null;
+        InstanceIdentifier<Subnetmap> id = buildSubnetmapIdentifier(subnetUuid);
+        Optional<Subnetmap> optionalSn = read(broker, LogicalDatastoreType.CONFIGURATION, id);
+        if (optionalSn.isPresent()) {
+            sn = optionalSn.get();
+        }
+        return sn;
+    }
+
+    public static boolean isSubnetPartOfVpn(Subnetmap sn, String vpnName) {
+        if (vpnName == null || sn == null || sn.getVpnId() == null) {
+            return false;
+        }
+        if (sn.getVpnId().getValue().equals(vpnName)) {
+            return true;
+        } else if (sn.getInternetVpnId() != null
+                && sn.getInternetVpnId().getValue().equals(vpnName)) {
+            return true;
+        }
+        return false;
+    }
+
+    public static boolean isAdjacencyEligibleToVpnInternet(DataBroker dataBroker, Adjacency adjacency) {
+        // returns true if BGPVPN Internet and adjacency is IPv6, false otherwise
+        boolean adjacencyEligible = true;
+        if (adjacency.getAdjacencyType() == AdjacencyType.ExtraRoute) {
+            if (FibHelper.isIpv6Prefix(adjacency.getIpAddress())) {
+                return adjacencyEligible;
+            }
+            return false;
+        } else if (adjacency.getSubnetId() == null) {
+            return adjacencyEligible;
+        }
+        Subnetmap sn = VpnUtil.getSubnetmapFromItsUuid(
+                   dataBroker, adjacency.getSubnetId());
+        if (sn != null && sn.getInternetVpnId() != null) {
+            adjacencyEligible = false;
+        }
+        return adjacencyEligible;
+    }
+
+    public static boolean isAdjacencyEligibleToVpn(DataBroker dataBroker, Adjacency adjacency,
+                      String vpnName, String interfaceName) {
+        // returns true if BGPVPN Internet and adjacency is IPv6, false otherwise
+        boolean adjacencyEligible = true;
+        // if BGPVPN internet, return false if subnetmap has not internetVpnId() filled in
+        if (isBgpVpnInternet(dataBroker, vpnName)) {
+            return isAdjacencyEligibleToVpnInternet(dataBroker, adjacency);
+        }
+        return adjacencyEligible;
+    }
+
+    public static String getInternetVpnFromVpnInstanceList(DataBroker dataBroker,
+                                        List<VpnInstanceNames> vpnInstanceList) {
+        for (VpnInstanceNames vpnInstance : vpnInstanceList) {
+            String vpnName = vpnInstance.getVpnName();
+            if (isBgpVpnInternet(dataBroker, vpnName)) {
+                return vpnName;
+            }
+        }
+        return null;
+    }
+
+    /** Get boolean true if vpn is bgpvpn internet, false otherwise.
+     * @param dataBroker databroker for transaction
+     * @param vpnName name of the input VPN
+     * @return true or false
+     */
+    public static boolean isBgpVpnInternet(DataBroker dataBroker, String vpnName) {
+        String primaryRd = getVpnRd(dataBroker, vpnName);
+        if (primaryRd == null) {
+            LOG.error("isBgpVpnInternet VPN {}."
+                      + "Primary RD not found", vpnName);
+            return false;
+        }
+        InstanceIdentifier<VpnInstanceOpDataEntry> id = InstanceIdentifier.builder(VpnInstanceOpData.class)
+              .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(primaryRd)).build();
+
+        Optional<VpnInstanceOpDataEntry> vpnInstanceOpDataEntryOptional =
+            read(dataBroker, LogicalDatastoreType.OPERATIONAL, id);
+        if (!vpnInstanceOpDataEntryOptional.isPresent()) {
+            LOG.error("isBgpVpnInternet VPN {}."
+                     + "VpnInstanceOpDataEntry not found", vpnName);
+            return false;
+        }
+        LOG.debug("isBgpVpnInternet VPN {}."
+             + "Successfully VpnInstanceOpDataEntry.getBgpvpnType {}",
+             vpnName, vpnInstanceOpDataEntryOptional.get().getBgpvpnType());
+        if (vpnInstanceOpDataEntryOptional.get().getBgpvpnType() == VpnInstanceOpDataEntry
+               .BgpvpnType.BGPVPNInternet) {
+            return true;
+        }
+        return false;
+    }
+
+    /**Get IpVersionChoice from String IP like x.x.x.x or an representation IPv6.
+     * @param ipAddress String of an representation IP address V4 or V6
+     * @return the IpVersionChoice of the version or IpVersionChoice.UNDEFINED otherwise
+     */
+    public static IpVersionChoice getIpVersionFromString(String ipAddress) {
+        IpVersionChoice ipchoice = IpVersionChoice.UNDEFINED;
+        int indexIpAddress = ipAddress.indexOf('/');
+        if (indexIpAddress >= 0) {
+            ipAddress = ipAddress.substring(0, indexIpAddress);
+        }
+        try {
+            InetAddress address = InetAddress.getByName(ipAddress);
+            if (address instanceof Inet4Address) {
+                return IpVersionChoice.IPV4;
+            } else if (address instanceof Inet6Address) {
+                return IpVersionChoice.IPV6;
+            }
+        } catch (UnknownHostException | SecurityException e) {
+            ipchoice = IpVersionChoice.UNDEFINED;
+        }
+        return ipchoice;
+    }
+
 }