NETVIRT-1630 migrate to md-sal APIs
[netvirt.git] / neutronvpn / impl / src / main / java / org / opendaylight / netvirt / neutronvpn / NeutronvpnUtils.java
index cacacf9844b29132bda550ebc5368a916bf2111d..3231943ad0d2adf0a681f10d317883a5249a9aa9 100644 (file)
@@ -5,16 +5,19 @@
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
  * and is available at http://www.eclipse.org/legal/epl-v10.html
  */
-
 package org.opendaylight.netvirt.neutronvpn;
 
+import static org.opendaylight.genius.infra.Datastore.CONFIGURATION;
 import static org.opendaylight.genius.infra.Datastore.OPERATIONAL;
-import static org.opendaylight.netvirt.neutronvpn.api.utils.NeutronUtils.requireNonNullElse;
 
-import com.google.common.base.Optional;
+import com.google.common.base.Function;
 import com.google.common.collect.ImmutableBiMap;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
-import java.math.BigInteger;
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.google.common.util.concurrent.SettableFuture;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -22,42 +25,37 @@ import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
-import java.util.stream.Collectors;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
+import java.util.concurrent.locks.ReentrantLock;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import org.apache.commons.lang3.StringUtils;
-import org.opendaylight.controller.md.sal.binding.api.DataBroker;
-import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
-import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
 import org.opendaylight.genius.datastoreutils.SingleTransactionDataBroker;
 import org.opendaylight.genius.infra.Datastore;
 import org.opendaylight.genius.infra.ManagedNewTransactionRunner;
 import org.opendaylight.genius.infra.ManagedNewTransactionRunnerImpl;
 import org.opendaylight.genius.infra.TypedWriteTransaction;
 import org.opendaylight.genius.mdsalutil.MDSALUtil;
+import org.opendaylight.genius.utils.JvmGlobalLocks;
 import org.opendaylight.infrautils.jobcoordinator.JobCoordinator;
 import org.opendaylight.infrautils.utils.concurrent.ListenableFutures;
+import org.opendaylight.infrautils.utils.concurrent.LoggingFutures;
+import org.opendaylight.mdsal.binding.api.DataBroker;
+import org.opendaylight.mdsal.binding.api.ReadTransaction;
+import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
 import org.opendaylight.netvirt.neutronvpn.api.enums.IpVersionChoice;
+import org.opendaylight.netvirt.neutronvpn.api.utils.NeutronConstants;
 import org.opendaylight.netvirt.neutronvpn.api.utils.NeutronUtils;
-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;
-import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.instances.VpnInstance;
-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.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv6Address;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.rev140508.Interfaces;
@@ -66,26 +64,20 @@ import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.interfaces.
 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.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.ReleaseIdInput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdInputBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.ReleaseIdOutput;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.Dhcpv6Base;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.InterfaceAcl;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.InterfaceAclBuilder;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.IpPrefixOrAddress;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.IpVersionBase;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.PortSubnets;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.interfaces._interface.AllowedAddressPairs;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.interfaces._interface.AllowedAddressPairsBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.PortSubnet;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.PortSubnetBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.PortSubnetKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.port.subnet.SubnetInfo;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.port.subnet.SubnetInfoBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.port.subnets.port.subnet.SubnetInfoKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.interfaces._interface.SubnetInfo;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.interfaces._interface.SubnetInfoBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.aclservice.rev160608.interfaces._interface.SubnetInfoKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.SegmentTypeBase;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.SegmentTypeFlat;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.SegmentTypeGre;
@@ -113,12 +105,22 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev16011
 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.floating.ip.port.info.FloatingIpIdToPortMapping;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.port.info.FloatingIpIdToPortMappingKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.VpnInstances;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.VpnInterfaces;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.vpn.instances.VpnInstance;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.vpn.instances.VpnInstanceBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.vpn.instances.VpnInstanceKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.vpn.interfaces.VpnInterface;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.l3vpn.rev200204.vpn.interfaces.VpnInterfaceKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NetworkMaps;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NeutronVpnPortIdSubportData;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.NeutronVpnPortipPortData;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.Subnetmaps;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.VpnMaps;
 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.port.id.subport.data.PortIdToSubport;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.neutron.vpn.port.id.subport.data.PortIdToSubportKey;
 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;
@@ -147,7 +149,6 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.por
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.ports.PortKey;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.portsecurity.rev150712.PortSecurityExtension;
 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.provider.ext.rev150712.NetworkProviderExtension;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.qos.rev160613.qos.attributes.qos.policies.QosPolicy;
 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;
@@ -160,6 +161,7 @@ import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netvirt.
 import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.opendaylight.yangtools.yang.common.RpcResult;
+import org.opendaylight.yangtools.yang.common.Uint64;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -176,29 +178,38 @@ public class NeutronvpnUtils {
             .put(NetworkTypeVxlan.class, SegmentTypeVxlan.class)
             .build();
 
-    private static final Set<Class<? extends NetworkTypeBase>> SUPPORTED_NETWORK_TYPES = new HashSet<>();
-
-    static {
-        SUPPORTED_NETWORK_TYPES.add(NetworkTypeFlat.class);
-        SUPPORTED_NETWORK_TYPES.add(NetworkTypeVlan.class);
-        SUPPORTED_NETWORK_TYPES.add(NetworkTypeVxlan.class);
-        SUPPORTED_NETWORK_TYPES.add(NetworkTypeGre.class);
-    }
+    private static final ImmutableSet<Class<? extends NetworkTypeBase>> SUPPORTED_NETWORK_TYPES = ImmutableSet.of(
+        NetworkTypeFlat.class,
+        NetworkTypeVlan.class,
+        NetworkTypeVxlan.class,
+        NetworkTypeGre.class);
+
+
+    private static final InstanceIdentifier<VpnInstanceOpData> VPN_INSTANCE_OP_DATA_IID =
+            InstanceIdentifier.create(VpnInstanceOpData.class);
+    private static final InstanceIdentifier<VpnMaps> VPN_MAPS_IID = InstanceIdentifier.create(VpnMaps.class);
+    private static final InstanceIdentifier<Subnetmaps> SUBNETMAPS_IID = InstanceIdentifier.create(Subnetmaps.class);
+    private static final InstanceIdentifier<Networks> NEUTRON_NETWORKS_IID = InstanceIdentifier.builder(Neutron.class)
+            .child(Networks.class).build();
+    private static final InstanceIdentifier<Ports> NEUTRON_PORTS_IID = InstanceIdentifier.builder(Neutron.class)
+            .child(Ports.class).build();
+    private static final InstanceIdentifier<Routers> NEUTRON_ROUTERS_IID = InstanceIdentifier.builder(Neutron.class)
+            .child(Routers.class).build();
+    private static final InstanceIdentifier<Subnets> NEUTRON_SUBNETS_IID = InstanceIdentifier.builder(Neutron.class)
+            .child(Subnets.class).build();
 
     private final ConcurrentMap<Uuid, Network> networkMap = new ConcurrentHashMap<>();
     private final ConcurrentMap<Uuid, Router> routerMap = new ConcurrentHashMap<>();
     private final ConcurrentMap<Uuid, Port> portMap = new ConcurrentHashMap<>();
     private final ConcurrentMap<Uuid, Subnet> subnetMap = new ConcurrentHashMap<>();
     private final Map<IpAddress, Set<Uuid>> subnetGwIpMap = new ConcurrentHashMap<>();
-    private final ConcurrentMap<Uuid, QosPolicy> qosPolicyMap = new ConcurrentHashMap<>();
-    private final ConcurrentMap<Uuid, HashMap<Uuid, Port>> qosPortsMap = new ConcurrentHashMap<>();
-    private final ConcurrentMap<Uuid, HashMap<Uuid, Network>> qosNetworksMap = new ConcurrentHashMap<>();
 
     private final DataBroker dataBroker;
     private final ManagedNewTransactionRunner txRunner;
     private final IdManagerService idManager;
     private final JobCoordinator jobCoordinator;
     private final IPV6InternetDefaultRouteProgrammer ipV6InternetDefRt;
+    private static final int JOB_MAX_RETRIES = 3;
 
     @Inject
     public NeutronvpnUtils(final DataBroker dataBroker, final IdManagerService idManager,
@@ -224,9 +235,7 @@ public class NeutronvpnUtils {
 
     @Nullable
     public VpnMap getVpnMap(Uuid id) {
-        InstanceIdentifier<VpnMap> vpnMapIdentifier = InstanceIdentifier.builder(VpnMaps.class).child(VpnMap.class,
-                new VpnMapKey(id)).build();
-        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier);
+        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier(id));
         if (optionalVpnMap.isPresent()) {
             return optionalVpnMap.get();
         }
@@ -236,11 +245,9 @@ public class NeutronvpnUtils {
 
     @Nullable
     protected Uuid getVpnForNetwork(Uuid network) {
-        InstanceIdentifier<VpnMaps> vpnMapsIdentifier = InstanceIdentifier.builder(VpnMaps.class).build();
-        Optional<VpnMaps> optionalVpnMaps = read(LogicalDatastoreType.CONFIGURATION, vpnMapsIdentifier);
-        if (optionalVpnMaps.isPresent() && optionalVpnMaps.get().getVpnMap() != null) {
-            for (VpnMap vpnMap : requireNonNullElse(optionalVpnMaps.get().getVpnMap(),
-                    Collections.<VpnMap>emptyList())) {
+        Optional<VpnMaps> optionalVpnMaps = read(LogicalDatastoreType.CONFIGURATION, VPN_MAPS_IID);
+        if (optionalVpnMaps.isPresent() && optionalVpnMaps.get().nonnullVpnMap() != null) {
+            for (VpnMap vpnMap : new ArrayList<>(optionalVpnMaps.get().nonnullVpnMap())) {
                 List<Uuid> netIds = vpnMap.getNetworkIds();
                 if (netIds != null && netIds.contains(network)) {
                     return vpnMap.getVpnId();
@@ -282,27 +289,20 @@ public class NeutronvpnUtils {
             return null;
         }
 
-        InstanceIdentifier<VpnMaps> vpnMapsIdentifier = InstanceIdentifier.builder(VpnMaps.class).build();
-        Optional<VpnMaps> optionalVpnMaps = read(LogicalDatastoreType.CONFIGURATION, vpnMapsIdentifier);
-        if (optionalVpnMaps.isPresent() && optionalVpnMaps.get().getVpnMap() != null) {
-            for (VpnMap vpnMap : requireNonNullElse(optionalVpnMaps.get().getVpnMap(),
-                    Collections.<VpnMap>emptyList())) {
+        Optional<VpnMaps> optionalVpnMaps = read(LogicalDatastoreType.CONFIGURATION, VPN_MAPS_IID);
+        if (optionalVpnMaps.isPresent() && optionalVpnMaps.get().nonnullVpnMap() != null) {
+            for (VpnMap vpnMap : new ArrayList<>(optionalVpnMaps.get().nonnullVpnMap())) {
                 List<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.vpnmaps.vpnmap
                     .RouterIds> routerIdsList = vpnMap.getRouterIds();
                 if (routerIdsList == null || routerIdsList.isEmpty()) {
                     continue;
                 }
                 // Skip router vpnId fetching from internet BGP-VPN
-                if (vpnMap.getNetworkIds() != null && !vpnMap.getNetworkIds().isEmpty()) {
-                    // We only need to check the first network; if it’s not an external network there’s no
-                    // need to check the rest of the VPN’s network list
-                    if (getIsExternal(getNeutronNetwork(vpnMap.getNetworkIds().iterator().next()))) {
-                        continue;
-                    }
+                if (hasExternalNetwork(vpnMap.getNetworkIds())) {
+                    continue;
                 }
-                List<Uuid> rtrIdsList = routerIdsList.stream().map(routerIds -> routerIds.getRouterId())
-                        .collect(Collectors.toList());
-                if (rtrIdsList.contains(routerId)) {
+                // FIXME: NETVIRT-1503: this check can be replaced by a ReadOnlyTransaction.exists()
+                if (routerIdsList.stream().anyMatch(routerIds -> routerId.equals(routerIds.getRouterId()))) {
                     if (externalVpn) {
                         if (!routerId.equals(vpnMap.getVpnId())) {
                             return vpnMap.getVpnId();
@@ -319,11 +319,29 @@ public class NeutronvpnUtils {
         return null;
     }
 
+    // We only need to check the first network; if it’s not an external network there’s no
+    // need to check the rest of the VPN’s network list. Note that some UUIDs may point to unknown networks, in which
+    // case we check more  and assume false.
+    private boolean hasExternalNetwork(List<Uuid> uuids) {
+        if (uuids != null) {
+            for (Uuid uuid : uuids) {
+                final Network network = getNeutronNetwork(uuid);
+                if (network != null) {
+                    if (Boolean.TRUE.equals(getIsExternal(network))) {
+                        return true;
+                    }
+                } else {
+                    LOG.debug("hasExternalNetwork: cannot find network for {}", uuid);
+                }
+            }
+        }
+        return false;
+    }
+
+
     @Nullable
     protected List<Uuid> getRouterIdListforVpn(Uuid vpnId) {
-        InstanceIdentifier<VpnMap> vpnMapIdentifier = InstanceIdentifier.builder(VpnMaps.class).child(VpnMap.class,
-                new VpnMapKey(vpnId)).build();
-        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier);
+        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier(vpnId));
         if (optionalVpnMap.isPresent()) {
             VpnMap vpnMap = optionalVpnMap.get();
             return NeutronUtils.getVpnMapRouterIdsListUuid(vpnMap.getRouterIds());
@@ -334,12 +352,14 @@ public class NeutronvpnUtils {
 
     @Nullable
     protected List<Uuid> getNetworksForVpn(Uuid vpnId) {
-        InstanceIdentifier<VpnMap> vpnMapIdentifier = InstanceIdentifier.builder(VpnMaps.class).child(VpnMap.class,
-                new VpnMapKey(vpnId)).build();
-        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier);
+        Optional<VpnMap> optionalVpnMap = read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier(vpnId));
         if (optionalVpnMap.isPresent()) {
             VpnMap vpnMap = optionalVpnMap.get();
-            return vpnMap.getNetworkIds();
+            if (vpnMap.getNetworkIds() != null && !vpnMap.getNetworkIds().isEmpty()) {
+                return new ArrayList<>(vpnMap.getNetworkIds());
+            } else {
+                return null;
+            }
         }
         LOG.error("getNetworksforVpn: Failed as VPNMaps DS is absent for VPN {}", vpnId.getValue());
         return null;
@@ -348,8 +368,7 @@ public class NeutronvpnUtils {
     protected List<Uuid> getSubnetsforVpn(Uuid vpnid) {
         List<Uuid> subnets = new ArrayList<>();
         // read subnetmaps
-        InstanceIdentifier<Subnetmaps> subnetmapsid = InstanceIdentifier.builder(Subnetmaps.class).build();
-        Optional<Subnetmaps> subnetmaps = read(LogicalDatastoreType.CONFIGURATION, subnetmapsid);
+        Optional<Subnetmaps> subnetmaps = read(LogicalDatastoreType.CONFIGURATION, SUBNETMAPS_IID);
         if (subnetmaps.isPresent() && subnetmaps.get().getSubnetmap() != null) {
             List<Subnetmap> subnetMapList = subnetmaps.get().getSubnetmap();
             for (Subnetmap candidateSubnetMap : subnetMapList) {
@@ -384,24 +403,12 @@ public class NeutronvpnUtils {
         return null;
     }
 
-    @Nullable
-    protected List<Uuid> getPortIdsFromSubnetId(Uuid subnetId) {
-        InstanceIdentifier<Subnetmap> id = buildSubnetMapIdentifier(subnetId);
-        Optional<Subnetmap> optionalSubnetmap = read(LogicalDatastoreType.CONFIGURATION, id);
-        if (optionalSubnetmap.isPresent()) {
-            return optionalSubnetmap.get().getPortList();
-        }
-        return null;
-    }
-
     protected Router getNeutronRouter(Uuid routerId) {
         Router router = routerMap.get(routerId);
         if (router != null) {
             return router;
         }
-        InstanceIdentifier<Router> inst = InstanceIdentifier.create(Neutron.class).child(Routers.class).child(Router
-                .class, new RouterKey(routerId));
-        Optional<Router> rtr = read(LogicalDatastoreType.CONFIGURATION, inst);
+        Optional<Router> rtr = read(LogicalDatastoreType.CONFIGURATION, getNeutronRouterIid(routerId));
         if (rtr.isPresent()) {
             router = rtr.get();
         }
@@ -409,40 +416,52 @@ public class NeutronvpnUtils {
     }
 
     public InstanceIdentifier<Router> getNeutronRouterIid(Uuid routerId) {
-        return InstanceIdentifier.create(Neutron.class).child(Routers.class).child(Router
-                .class, new RouterKey(routerId));
-
+        return NEUTRON_ROUTERS_IID.child(Router.class, new RouterKey(routerId));
     }
 
-    protected Network getNeutronNetwork(Uuid networkId) {
-        Network network = null;
-        network = networkMap.get(networkId);
+    protected @Nullable Network getNeutronNetwork(Uuid networkId) {
+        Network network = networkMap.get(networkId);
         if (network != null) {
             return network;
         }
         LOG.debug("getNeutronNetwork for {}", networkId.getValue());
-        InstanceIdentifier<Network> inst = InstanceIdentifier.create(Neutron.class).child(Networks.class)
-            .child(Network.class, new NetworkKey(networkId));
-        Optional<Network> net = read(LogicalDatastoreType.CONFIGURATION, inst);
-        if (net.isPresent()) {
-            network = net.get();
-        }
-        return network;
+        InstanceIdentifier<Network> inst = NEUTRON_NETWORKS_IID.child(Network.class, new NetworkKey(networkId));
+        return read(LogicalDatastoreType.CONFIGURATION, inst).orElse(null);
     }
 
-    protected Port getNeutronPort(Uuid portId) {
+    protected @Nullable Port getNeutronPort(Uuid portId) {
         Port prt = portMap.get(portId);
         if (prt != null) {
             return prt;
         }
         LOG.debug("getNeutronPort for {}", portId.getValue());
-        InstanceIdentifier<Port> inst = InstanceIdentifier.create(Neutron.class).child(Ports.class).child(Port.class,
-                new PortKey(portId));
-        Optional<Port> port = read(LogicalDatastoreType.CONFIGURATION, inst);
-        if (port.isPresent()) {
-            prt = port.get();
+        InstanceIdentifier<Port> inst = NEUTRON_PORTS_IID.child(Port.class, new PortKey(portId));
+        return read(LogicalDatastoreType.CONFIGURATION, inst).orElse(null);
+    }
+
+    public PortIdToSubport getPortIdToSubport(Uuid portId) {
+        InstanceIdentifier<PortIdToSubport> portIdToSubportIdentifier = buildPortIdSubportMappingIdentifier(portId);
+        Optional<PortIdToSubport> optionalPortIdToSubport = read(LogicalDatastoreType.CONFIGURATION,
+                portIdToSubportIdentifier);
+        if (optionalPortIdToSubport.isPresent()) {
+            return optionalPortIdToSubport.get();
         }
-        return prt;
+        LOG.error("getPortIdToSubport failed, PortIdToSubport {} not present", portId.getValue());
+        return null;
+    }
+
+    protected static boolean isDhcpServerPort(Port port) {
+        return port.getDeviceOwner().equals("network:dhcp");
+    }
+
+    protected InterfaceAcl getDhcpInterfaceAcl(Port port) {
+        InterfaceAclBuilder interfaceAclBuilder = new InterfaceAclBuilder();
+        interfaceAclBuilder.setPortSecurityEnabled(false);
+        interfaceAclBuilder.setInterfaceType(InterfaceAcl.InterfaceType.DhcpService);
+        List<AllowedAddressPairs> aclAllowedAddressPairs = NeutronvpnUtils.getAllowedAddressPairsForAclService(
+                port.getMacAddress(), port.getFixedIps());
+        interfaceAclBuilder.setAllowedAddressPairs(aclAllowedAddressPairs);
+        return interfaceAclBuilder.build();
     }
 
     /**
@@ -727,7 +746,7 @@ public class NeutronvpnUtils {
      * @param interfaceAclBuilder the interface acl builder
      * @param port the port
      */
-    protected static void populateInterfaceAclBuilder(InterfaceAclBuilder interfaceAclBuilder, Port port) {
+    protected void populateInterfaceAclBuilder(InterfaceAclBuilder interfaceAclBuilder, Port port) {
         // Handle security group enabled
         List<Uuid> securityGroups = port.getSecurityGroups();
         if (securityGroups != null) {
@@ -743,23 +762,14 @@ public class NeutronvpnUtils {
             aclAllowedAddressPairs.addAll(NeutronvpnUtils.getAllowedAddressPairsForAclService(portAllowedAddressPairs));
         }
         interfaceAclBuilder.setAllowedAddressPairs(aclAllowedAddressPairs);
+        interfaceAclBuilder.setInterfaceType(InterfaceAcl.InterfaceType.AccessPort);
+        populateSubnetInfo(interfaceAclBuilder, port);
     }
 
-    protected void populateSubnetInfo(Port port) {
+    protected void populateSubnetInfo(InterfaceAclBuilder interfaceAclBuilder, Port port) {
         List<SubnetInfo> portSubnetInfo = getSubnetInfo(port);
         if (portSubnetInfo != null) {
-            String portId = port.getUuid().getValue();
-            InstanceIdentifier<PortSubnet> portSubnetIdentifier = buildPortSubnetIdentifier(portId);
-
-            PortSubnetBuilder portSubnetBuilder = new PortSubnetBuilder().withKey(new PortSubnetKey(portId))
-                    .setPortId(portId).setSubnetInfo(portSubnetInfo);
-            try {
-                SingleTransactionDataBroker.syncWrite(dataBroker, LogicalDatastoreType.OPERATIONAL,
-                        portSubnetIdentifier, portSubnetBuilder.build());
-            } catch (TransactionCommitFailedException e) {
-                LOG.error("Failed to populate subnet info for port={}", portId, e);
-            }
-            LOG.debug("Created Subnet info for port={}", portId);
+            interfaceAclBuilder.setSubnetInfo(portSubnetInfo);
         }
     }
 
@@ -776,9 +786,9 @@ public class NeutronvpnUtils {
             Subnet subnet = getNeutronSubnet(subnetId);
             if (subnet != null) {
                 Class<? extends IpVersionBase> ipVersion =
-                        NeutronSecurityRuleConstants.IP_VERSION_MAP.get(subnet.getIpVersion());
+                        NeutronSecurityGroupConstants.IP_VERSION_MAP.get(subnet.getIpVersion());
                 Class<? extends Dhcpv6Base> raMode = subnet.getIpv6RaMode() == null ? null
-                        : NeutronSecurityRuleConstants.RA_MODE_MAP.get(subnet.getIpv6RaMode());
+                        : NeutronSecurityGroupConstants.RA_MODE_MAP.get(subnet.getIpv6RaMode());
                 SubnetInfo subnetInfo = new SubnetInfoBuilder().withKey(new SubnetInfoKey(subnetId))
                         .setIpVersion(ipVersion).setIpPrefix(new IpPrefixOrAddress(subnet.getCidr()))
                         .setIpv6RaMode(raMode).setGatewayIp(subnet.getGatewayIp()).build();
@@ -793,8 +803,7 @@ public class NeutronvpnUtils {
         if (subnet != null) {
             return subnet;
         }
-        InstanceIdentifier<Subnet> inst = InstanceIdentifier.create(Neutron.class).child(Subnets.class).child(Subnet
-                .class, new SubnetKey(subnetId));
+        InstanceIdentifier<Subnet> inst = NEUTRON_SUBNETS_IID.child(Subnet.class, new SubnetKey(subnetId));
         Optional<Subnet> sn = read(LogicalDatastoreType.CONFIGURATION, inst);
 
         if (sn.isPresent()) {
@@ -806,8 +815,7 @@ public class NeutronvpnUtils {
 
     protected List<Subnetmap> getNeutronRouterSubnetMapList(Uuid routerId) {
         List<Subnetmap> subnetMapList = new ArrayList<>();
-        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION,
-                InstanceIdentifier.builder(Subnetmaps.class).build());
+        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION, SUBNETMAPS_IID);
         if (subnetMaps.isPresent() && subnetMaps.get().getSubnetmap() != null) {
             for (Subnetmap subnetmap : subnetMaps.get().getSubnetmap()) {
                 if (routerId.equals(subnetmap.getRouterId())) {
@@ -819,12 +827,11 @@ public class NeutronvpnUtils {
         return subnetMapList;
     }
 
-    @Nonnull
+    @NonNull
     protected List<Uuid> getNeutronRouterSubnetIds(Uuid routerId) {
         LOG.debug("getNeutronRouterSubnetIds for {}", routerId.getValue());
         List<Uuid> subnetIdList = new ArrayList<>();
-        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION,
-            InstanceIdentifier.builder(Subnetmaps.class).build());
+        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION, SUBNETMAPS_IID);
         if (subnetMaps.isPresent() && subnetMaps.get().getSubnetmap() != null) {
             for (Subnetmap subnetmap : subnetMaps.get().getSubnetmap()) {
                 if (routerId.equals(subnetmap.getRouterId())) {
@@ -841,11 +848,9 @@ public class NeutronvpnUtils {
     @Nullable
     protected Short getIPPrefixFromPort(Port port) {
         try {
-            Uuid subnetUUID = port.getFixedIps().get(0).getSubnetId();
-            SubnetKey subnetkey = new SubnetKey(subnetUUID);
-            InstanceIdentifier<Subnet> subnetidentifier = InstanceIdentifier.create(Neutron.class).child(Subnets
-                    .class).child(Subnet.class, subnetkey);
-            Optional<Subnet> subnet = read(LogicalDatastoreType.CONFIGURATION, subnetidentifier);
+            // FIXME: why are we not using getNeutronSubnet() here? it does caching for us...
+            Optional<Subnet> subnet = read(LogicalDatastoreType.CONFIGURATION,
+                NEUTRON_SUBNETS_IID.child(Subnet.class, new SubnetKey(port.getFixedIps().get(0).getSubnetId())));
             if (subnet.isPresent()) {
                 String cidr = subnet.get().getCidr().stringValue();
                 // Extract the prefix length from cidr
@@ -883,8 +888,8 @@ public class NeutronvpnUtils {
             LOG.trace("Neutron port with fixedIp: {}, vpn {}, interface {}, mac {}, isSubnetIp {} added to "
                 + "VpnPortipToPort DS", fixedIp, vpnName, portName, macAddress, isSubnetIp);
         } catch (Exception e) {
-            LOG.error("Failure while creating VPNPortFixedIpToPort map for vpn {} - fixedIP {}", vpnName, fixedIp,
-                    e);
+            LOG.error("Failure while creating VPNPortFixedIpToPort map for vpn {} - fixedIP {} for port {} with "
+                    + "macAddress {}", vpnName, fixedIp, portName, macAddress, e);
         }
     }
 
@@ -899,7 +904,7 @@ public class NeutronvpnUtils {
             } else {
                 MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
             }
-            LOG.trace("Neutron router port with fixedIp: {}, vpn {} removed from LearntVpnPortipToPort DS", fixedIp,
+            LOG.trace("Neutron router port with fixedIp: {}, vpn {} removed from VpnPortipToPort DS", fixedIp,
                     vpnName);
         } catch (Exception e) {
             LOG.error("Failure while removing VPNPortFixedIpToPort map for vpn {} - fixedIP {}", vpnName, fixedIp,
@@ -911,15 +916,18 @@ public class NeutronvpnUtils {
     @SuppressWarnings("checkstyle:IllegalCatch")
     protected void removeLearntVpnVipToPort(String vpnName, String fixedIp) {
         InstanceIdentifier<LearntVpnVipToPort> id = NeutronvpnUtils.buildLearntVpnVipToPortIdentifier(vpnName, fixedIp);
+        // FIXME: can we use 'id' as the lock name?
+        final ReentrantLock lock = JvmGlobalLocks.getLockForString(vpnName + fixedIp);
+        lock.lock();
         try {
-            synchronized ((vpnName + fixedIp).intern()) {
-                MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.OPERATIONAL, id);
-            }
+            MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.OPERATIONAL, id);
             LOG.trace("Neutron router port with fixedIp: {}, vpn {} removed from LearntVpnPortipToPort DS", fixedIp,
                     vpnName);
         } catch (Exception e) {
             LOG.error("Failure while removing LearntVpnPortFixedIpToPort map for vpn {} - fixedIP {}",
                 vpnName, fixedIp, e);
+        } finally {
+            lock.unlock();
         }
     }
 
@@ -1010,52 +1018,8 @@ public class NeutronvpnUtils {
     }
 
     static Boolean getIsExternal(Network network) {
-        return network.augmentation(NetworkL3Extension.class) != null
-                && network.augmentation(NetworkL3Extension.class).isExternal();
-    }
-
-    public void addToQosPolicyCache(QosPolicy qosPolicy) {
-        qosPolicyMap.put(qosPolicy.getUuid(),qosPolicy);
-    }
-
-    public void removeFromQosPolicyCache(QosPolicy qosPolicy) {
-        qosPolicyMap.remove(qosPolicy.getUuid());
-    }
-
-    public void addToQosPortsCache(Uuid qosUuid, Port port) {
-        if (qosPortsMap.containsKey(qosUuid)) {
-            if (!qosPortsMap.get(qosUuid).containsKey(port.getUuid())) {
-                qosPortsMap.get(qosUuid).put(port.getUuid(), port);
-            }
-        } else {
-            HashMap<Uuid, Port> newPortMap = new HashMap<>();
-            newPortMap.put(port.getUuid(), port);
-            qosPortsMap.put(qosUuid, newPortMap);
-        }
-    }
-
-    public void removeFromQosPortsCache(Uuid qosUuid, Port port) {
-        if (qosPortsMap.containsKey(qosUuid) && qosPortsMap.get(qosUuid).containsKey(port.getUuid())) {
-            qosPortsMap.get(qosUuid).remove(port.getUuid(), port);
-        }
-    }
-
-    public void addToQosNetworksCache(Uuid qosUuid, Network network) {
-        if (qosNetworksMap.containsKey(qosUuid)) {
-            if (!qosNetworksMap.get(qosUuid).containsKey(network.getUuid())) {
-                qosNetworksMap.get(qosUuid).put(network.getUuid(), network);
-            }
-        } else {
-            HashMap<Uuid, Network> newNetworkMap = new HashMap<>();
-            newNetworkMap.put(network.getUuid(), network);
-            qosNetworksMap.put(qosUuid, newNetworkMap);
-        }
-    }
-
-    public void removeFromQosNetworksCache(Uuid qosUuid, Network network) {
-        if (qosNetworksMap.containsKey(qosUuid) && qosNetworksMap.get(qosUuid).containsKey(network.getUuid())) {
-            qosNetworksMap.get(qosUuid).remove(network.getUuid(), network);
-        }
+        NetworkL3Extension ext = network.augmentation(NetworkL3Extension.class);
+        return ext != null && ext.isExternal();
     }
 
     static InstanceIdentifier<NetworkMap> buildNetworkMapIdentifier(Uuid networkId) {
@@ -1071,9 +1035,7 @@ public class NeutronvpnUtils {
     }
 
     static InstanceIdentifier<Subnetmap> buildSubnetMapIdentifier(Uuid subnetId) {
-        InstanceIdentifier<Subnetmap> id = InstanceIdentifier.builder(Subnetmaps.class).child(Subnetmap.class, new
-                SubnetmapKey(subnetId)).build();
-        return id;
+        return SUBNETMAPS_IID.child(Subnetmap.class, new SubnetmapKey(subnetId));
     }
 
     static InstanceIdentifier<Interface> buildVlanInterfaceIdentifier(String interfaceName) {
@@ -1082,6 +1044,12 @@ public class NeutronvpnUtils {
         return id;
     }
 
+    static InstanceIdentifier<PortIdToSubport> buildPortIdSubportMappingIdentifier(Uuid interfaceName) {
+        InstanceIdentifier<PortIdToSubport> id = InstanceIdentifier.builder(NeutronVpnPortIdSubportData.class)
+                .child(PortIdToSubport.class, new PortIdToSubportKey(interfaceName)).build();
+        return id;
+    }
+
     static InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext
             .routers.Routers> buildExtRoutersIdentifier(Uuid routerId) {
         InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers
@@ -1096,27 +1064,16 @@ public class NeutronvpnUtils {
                 FloatingIpIdToPortMappingKey(floatingIpId)).build();
     }
 
-    static InstanceIdentifier<PortSubnet> buildPortSubnetIdentifier(String portId) {
-        InstanceIdentifier<PortSubnet> id = InstanceIdentifier.builder(PortSubnets.class)
-                .child(PortSubnet.class, new PortSubnetKey(portId)).build();
-        return id;
-    }
-
     // TODO Remove this method entirely
     @SuppressWarnings("checkstyle:IllegalCatch")
     private <T extends DataObject> Optional<T> read(LogicalDatastoreType datastoreType, InstanceIdentifier<T> path) {
         try {
             return SingleTransactionDataBroker.syncReadOptional(dataBroker, datastoreType, path);
-        } catch (ReadFailedException e) {
+        } catch (ExecutionException | InterruptedException e) {
             throw new RuntimeException(e);
         }
     }
 
-    public static Class<? extends NetworkTypeBase> getNetworkType(Network network) {
-        NetworkProviderExtension providerExtension = network.augmentation(NetworkProviderExtension.class);
-        return providerExtension != null ? providerExtension.getNetworkType() : null;
-    }
-
     @Nullable
     static ProviderTypes getProviderNetworkType(Network network) {
         if (network == null) {
@@ -1145,22 +1102,23 @@ public class NeutronvpnUtils {
 
     static boolean isNetworkTypeSupported(Network network) {
         NetworkProviderExtension npe = network.augmentation(NetworkProviderExtension.class);
-        return npe != null && npe.getNetworkType() != null && SUPPORTED_NETWORK_TYPES.contains(npe.getNetworkType());
+        return npe != null && SUPPORTED_NETWORK_TYPES.contains(npe.getNetworkType());
     }
 
-    static boolean isNetworkOfType(Network network, Class<? extends NetworkTypeBase> type) {
-        NetworkProviderExtension npe = network.augmentation(NetworkProviderExtension.class);
-        if (npe != null && npe.getNetworkType() != null) {
-            return type.isAssignableFrom(npe.getNetworkType());
+    static boolean isFlatOrVlanNetwork(Network network) {
+        if (network != null) {
+            NetworkProviderExtension npe = network.augmentation(NetworkProviderExtension.class);
+            if (npe != null) {
+                Class<? extends NetworkTypeBase> npeType = npe.getNetworkType();
+                if (npeType != null) {
+                    return NetworkTypeVlan.class.isAssignableFrom(npeType)
+                            || NetworkTypeFlat.class.isAssignableFrom(npeType);
+                }
+            }
         }
         return false;
     }
 
-    static boolean isFlatOrVlanNetwork(Network network) {
-        return network != null
-                && (isNetworkOfType(network, NetworkTypeVlan.class) || isNetworkOfType(network, NetworkTypeFlat.class));
-    }
-
     static boolean isVlanOrVxlanNetwork(Class<? extends NetworkTypeBase> type) {
         return type.isAssignableFrom(NetworkTypeVxlan.class) || type.isAssignableFrom(NetworkTypeVlan.class);
     }
@@ -1185,74 +1143,40 @@ public class NeutronvpnUtils {
      */
     public Optional<InterVpnLink> getInterVpnLinkByEndpointIp(String endpointIp) {
         InstanceIdentifier<InterVpnLinks> interVpnLinksIid = InstanceIdentifier.builder(InterVpnLinks.class).build();
-        Optional<InterVpnLinks> interVpnLinksOpData = MDSALUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION,
-                interVpnLinksIid);
-        if (interVpnLinksOpData.isPresent()) {
-            for (InterVpnLink interVpnLink : requireNonNullElse(interVpnLinksOpData.get().getInterVpnLink(),
-                    Collections.<InterVpnLink>emptyList())) {
-                if (interVpnLink.getFirstEndpoint().getIpAddress().getValue().equals(endpointIp)
-                        || interVpnLink.getSecondEndpoint().getIpAddress().getValue().equals(endpointIp)) {
-                    return Optional.of(interVpnLink);
-                }
-            }
-        }
-        return Optional.absent();
-    }
-
-    public Set<RouterDpnList> getAllRouterDpnList(BigInteger dpid) {
-        Set<RouterDpnList> ret = new HashSet<>();
-        InstanceIdentifier<NeutronRouterDpns> routerDpnId =
-                InstanceIdentifier.create(NeutronRouterDpns.class);
-        Optional<NeutronRouterDpns> neutronRouterDpnsOpt =
-            MDSALUtil.read(dataBroker, LogicalDatastoreType.OPERATIONAL, routerDpnId);
-        if (neutronRouterDpnsOpt.isPresent()) {
-            NeutronRouterDpns neutronRouterDpns = neutronRouterDpnsOpt.get();
-            for (RouterDpnList routerDpnList : requireNonNullElse(neutronRouterDpns.getRouterDpnList(),
-                    Collections.<RouterDpnList>emptyList())) {
-                if (routerDpnList.getDpnVpninterfacesList() != null) {
-                    for (DpnVpninterfacesList dpnInterfaceList : routerDpnList.getDpnVpninterfacesList()) {
-                        if (dpnInterfaceList.getDpnId().equals(dpid)) {
-                            ret.add(routerDpnList);
-                        }
+        Optional<InterVpnLinks> interVpnLinksOpData = null;
+        try {
+            interVpnLinksOpData = MDSALUtil.read(dataBroker, LogicalDatastoreType.CONFIGURATION,
+                    interVpnLinksIid);
+            if (interVpnLinksOpData.isPresent()) {
+                for (InterVpnLink interVpnLink : interVpnLinksOpData.get().nonnullInterVpnLink()) {
+                    if (interVpnLink.getFirstEndpoint().getIpAddress().getValue().equals(endpointIp)
+                            || interVpnLink.getSecondEndpoint().getIpAddress().getValue().equals(endpointIp)) {
+                        return Optional.of(interVpnLink);
                     }
                 }
             }
+        } catch (ExecutionException | InterruptedException e) {
+            LOG.error("getInterVpnLinkByEndpointIp: Exception when reading intervpn Links for endpoint Ip {} ",
+                    endpointIp, e);
         }
-        return ret;
+        return Optional.empty();
     }
 
-    @Nullable
-    protected Integer getUniqueRDId(String poolName, String idKey) {
-        AllocateIdInput getIdInput = new AllocateIdInputBuilder().setPoolName(poolName).setIdKey(idKey).build();
-        try {
-            Future<RpcResult<AllocateIdOutput>> result = idManager.allocateId(getIdInput);
-            RpcResult<AllocateIdOutput> rpcResult = result.get();
-            if (rpcResult.isSuccessful()) {
-                return rpcResult.getResult().getIdValue().intValue();
-            } else {
-                LOG.error("RPC call to get unique ID for pool name {} with ID key {} returned with errors {}",
-                        poolName, idKey, rpcResult.getErrors());
-            }
-        } catch (InterruptedException | ExecutionException e) {
-            LOG.error("Exception when getting Unique Id for poolname {} and ID Key {}", poolName, idKey, e);
-        }
-        LOG.error("getUniqueRdId: Failed to return ID for poolname {} and ID Key {}", poolName, idKey);
-        return null;
-    }
-
-    protected void releaseRDId(String poolName, String idKey) {
+    protected Integer releaseId(String poolName, String idKey) {
         ReleaseIdInput idInput = new ReleaseIdInputBuilder().setPoolName(poolName).setIdKey(idKey).build();
         try {
-            RpcResult<ReleaseIdOutput> rpcResult = idManager.releaseId(idInput).get();
-            if (!rpcResult.isSuccessful()) {
-                LOG.error("RPC Call to Get Unique Id returned with errors for poolname {} and ID Key {}: {}",
-                        poolName, idKey, rpcResult.getErrors());
+            Future<RpcResult<ReleaseIdOutput>> result = idManager.releaseId(idInput);
+            if (result == null || result.get() == null || !result.get().isSuccessful()) {
+                LOG.error("releaseId: RPC Call to release Id from pool {} with key {} returned with Errors {}",
+                        poolName, idKey, (result != null && result.get() != null) ? result.get().getErrors() :
+                                "RpcResult is null");
             } else {
-                LOG.info("ID {} for RD released successfully", idKey);
+                return result.get().getResult().getIdValues().get(0).intValue();
             }
         } catch (InterruptedException | ExecutionException e) {
-            LOG.error("Exception when trying to release ID for poolname {} and ID Key {}", poolName, idKey, e);
+            LOG.error("releaseId: Exception when releasing Id for key {} from pool {}", idKey, poolName, e);
         }
+        return NeutronConstants.INVALID_ID;
     }
 
     protected static IpAddress getIpv6LinkLocalAddressFromMac(MacAddress mac) {
@@ -1303,10 +1227,7 @@ public class NeutronvpnUtils {
         Optional<VpnInstances> vpnInstancesOptional = read(LogicalDatastoreType.CONFIGURATION, path);
         if (vpnInstancesOptional.isPresent() && vpnInstancesOptional.get().getVpnInstance() != null) {
             for (VpnInstance vpnInstance : vpnInstancesOptional.get().getVpnInstance()) {
-                if (vpnInstance.getIpv4Family() == null) {
-                    continue;
-                }
-                List<String> rds = vpnInstance.getIpv4Family().getRouteDistinguisher();
+                List<String> rds = vpnInstance.getRouteDistinguisher();
                 if (rds != null) {
                     existingRDs.addAll(rds);
                 }
@@ -1316,9 +1237,7 @@ public class NeutronvpnUtils {
     }
 
     protected boolean doesVpnExist(Uuid vpnId) {
-        InstanceIdentifier<VpnMap> vpnMapIdentifier = InstanceIdentifier.builder(VpnMaps.class).child(VpnMap.class,
-                new VpnMapKey(vpnId)).build();
-        return read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier).isPresent();
+        return read(LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier(vpnId)).isPresent();
     }
 
     protected Optional<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.external
@@ -1390,8 +1309,7 @@ public class NeutronvpnUtils {
      */
     protected List<Subnetmap> getNeutronRouterSubnetMaps(Uuid routerId) {
         List<Subnetmap> subnetIdList = new ArrayList<>();
-        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION,
-            InstanceIdentifier.builder(Subnetmaps.class).build());
+        Optional<Subnetmaps> subnetMaps = read(LogicalDatastoreType.CONFIGURATION, SUBNETMAPS_IID);
         if (subnetMaps.isPresent() && subnetMaps.get().getSubnetmap() != null) {
             for (Subnetmap subnetmap : subnetMaps.get().getSubnetmap()) {
                 if (routerId.equals(subnetmap.getRouterId())) {
@@ -1422,7 +1340,7 @@ public class NeutronvpnUtils {
         InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
             .instance.to.vpn.id.VpnInstance> id = getVpnInstanceToVpnIdIdentifier(vpnName);
         return SingleTransactionDataBroker.syncReadOptionalAndTreatReadFailedExceptionAsAbsentOptional(dataBroker,
-                LogicalDatastoreType.CONFIGURATION, id).toJavaUtil().map(
+                LogicalDatastoreType.CONFIGURATION, id).map(
                 org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id
                         .VpnInstance::getVrfId).orElse(null);
     }
@@ -1478,8 +1396,7 @@ public class NeutronvpnUtils {
     }
 
     protected InstanceIdentifier<VpnInstanceOpDataEntry> getVpnOpDataIdentifier(String primaryRd) {
-        return InstanceIdentifier.builder(VpnInstanceOpData.class)
-                .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(primaryRd)).build();
+        return VPN_INSTANCE_OP_DATA_IID.child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(primaryRd));
     }
 
     public boolean shouldVpnHandleIpVersionChoiceChange(IpVersionChoice ipVersion, Uuid routerId, boolean add) {
@@ -1511,12 +1428,10 @@ public class NeutronvpnUtils {
         if (sm == null) {
             return false;
         }
-        InstanceIdentifier<Subnetmaps> subnetMapsId = InstanceIdentifier.builder(Subnetmaps.class).build();
-        Optional<Subnetmaps> allSubnetMaps = read(LogicalDatastoreType.CONFIGURATION, subnetMapsId);
+        Optional<Subnetmaps> allSubnetMaps = read(LogicalDatastoreType.CONFIGURATION, SUBNETMAPS_IID);
         // calculate and store in list IpVersion for each subnetMap, belonging to current VpnInstance
         List<IpVersionChoice> snIpVersions = new ArrayList<>();
-        for (Subnetmap snMap : requireNonNullElse(allSubnetMaps.get().getSubnetmap(),
-                Collections.<Subnetmap>emptyList())) {
+        for (Subnetmap snMap : allSubnetMaps.get().nonnullSubnetmap()) {
             if (snMap.getId().equals(sm.getId())) {
                 continue;
             }
@@ -1550,41 +1465,47 @@ public class NeutronvpnUtils {
     }
 
     public void updateVpnInstanceWithIpFamily(String vpnName, IpVersionChoice ipVersion, boolean add) {
-        VpnInstanceOpDataEntry vpnInstanceOpDataEntry = getVpnInstanceOpDataEntryFromVpnId(vpnName);
-        if (vpnInstanceOpDataEntry == null) {
-            return;
-        }
-        if (vpnInstanceOpDataEntry.getType() == VpnInstanceOpDataEntry.Type.L2) {
-            LOG.debug("updateVpnInstanceWithIpFamily: Update VpnInstance {} with ipFamily {}."
-                    + "VpnInstanceOpDataEntry is L2 instance. Do nothing.", vpnName, ipVersion);
-            return;
-        }
-        if (ipVersion == IpVersionChoice.UNDEFINED) {
-            LOG.debug("updateVpnInstanceWithIpFamily: Update VpnInstance {} with Undefined address family"
-                    + "is not allowed. Do nothing", vpnName);
-            return;
-        }
         jobCoordinator.enqueueJob("VPN-" + vpnName, () -> {
-            VpnInstanceOpDataEntryBuilder builder = new VpnInstanceOpDataEntryBuilder(vpnInstanceOpDataEntry);
+            VpnInstance vpnInstance = getVpnInstance(dataBroker, new Uuid(vpnName));
+            if (vpnInstance == null) {
+                return Collections.emptyList();
+            }
+            if (vpnInstance.isL2vpn()) {
+                LOG.debug("updateVpnInstanceWithIpFamily: Update VpnInstance {} with ipFamily {}."
+                        + "VpnInstance is L2 instance. Do nothing.", vpnName, ipVersion);
+                return Collections.emptyList();
+            }
+            if (ipVersion == IpVersionChoice.UNDEFINED) {
+                LOG.debug("updateVpnInstanceWithIpFamily: Update VpnInstance {} with Undefined address family"
+                        + "is not allowed. Do nothing", vpnName);
+                return Collections.emptyList();
+            }
+            VpnInstanceBuilder builder = new VpnInstanceBuilder(vpnInstance);
             boolean ipConfigured = add;
-            if (ipVersion.isIpVersionChosen(IpVersionChoice.IPV4AND6)) {
-                builder.setIpv4Configured(ipConfigured);
-                builder.setIpv6Configured(ipConfigured);
-            } else if (ipVersion.isIpVersionChosen(IpVersionChoice.IPV4)) {
-                builder.setIpv4Configured(ipConfigured);
-            } else if (ipVersion.isIpVersionChosen(IpVersionChoice.IPV6)) {
-                builder.setIpv6Configured(ipConfigured);
+
+            int originalValue = vpnInstance.getIpAddressFamilyConfigured().getIntValue();
+            int updatedValue = ipVersion.choice;
+
+            if (originalValue != updatedValue) {
+                if (ipConfigured) {
+                    originalValue = originalValue == 0 ? updatedValue : updatedValue + originalValue;
+                } else {
+                    originalValue = 10 - updatedValue;
+                }
+            } else if (!ipConfigured) {
+                originalValue = 0;
             }
+
+            builder.setIpAddressFamilyConfigured(VpnInstance.IpAddressFamilyConfigured.forValue(originalValue));
+
+            InstanceIdentifier<VpnInstance> vpnIdentifier = InstanceIdentifier.builder(VpnInstances.class)
+                    .child(VpnInstance.class, new VpnInstanceKey(vpnName)).build();
+            LOG.info("updateVpnInstanceWithIpFamily: Successfully {} IP family {} to Vpn {}",
+                    add == true ? "added" : "removed", ipVersion, vpnName);
             return Collections.singletonList(txRunner.callWithNewWriteOnlyTransactionAndSubmit(
-                    OPERATIONAL, tx -> {
-                    InstanceIdentifier<VpnInstanceOpDataEntry> id = InstanceIdentifier
-                            .builder(VpnInstanceOpData.class).child(VpnInstanceOpDataEntry.class,
-                                        new VpnInstanceOpDataEntryKey(vpnInstanceOpDataEntry.getVrfId())).build();
-                    tx.merge(id, builder.build(), false);
-                    LOG.info("updateVpnInstanceWithIpFamily: Successfully {} {} to Vpn {}",
-                            add == true ? "added" : "removed", ipVersion, vpnName);
-                }));
+                    CONFIGURATION, tx -> tx.merge(vpnIdentifier, builder.build(), false)));
         });
+        return;
     }
 
     /**
@@ -1610,7 +1531,7 @@ public class NeutronvpnUtils {
      * @param routerId the Uuid of the router which you try to reach the external network
      * @return Uuid of externalNetwork or null if is not exist
      */
-    protected Uuid getExternalNetworkUuidAttachedFromRouterUuid(@Nonnull Uuid routerId) {
+    protected Uuid getExternalNetworkUuidAttachedFromRouterUuid(@NonNull Uuid routerId) {
         LOG.debug("getExternalNetworkUuidAttachedFromRouterUuid for {}", routerId.getValue());
         Uuid externalNetworkUuid = null;
         Router router = getNeutronRouter(routerId);
@@ -1620,7 +1541,7 @@ public class NeutronvpnUtils {
         return externalNetworkUuid;
     }
 
-    public Uuid getInternetvpnUuidBoundToRouterId(@Nonnull Uuid routerId) {
+    public Uuid getInternetvpnUuidBoundToRouterId(@NonNull Uuid routerId) {
         Uuid netId = getExternalNetworkUuidAttachedFromRouterUuid(routerId);
         if (netId == null) {
             return netId;
@@ -1636,7 +1557,7 @@ public class NeutronvpnUtils {
      * @return Uuid of externalVpn or null if it is not found
      */
     @Nullable
-    public Uuid getInternetvpnUuidBoundToSubnetRouter(@Nonnull Uuid subnetUuid) {
+    public Uuid getInternetvpnUuidBoundToSubnetRouter(@NonNull Uuid subnetUuid) {
         Subnetmap subnetmap = getSubnetmap(subnetUuid);
         Uuid routerUuid = subnetmap.getRouterId();
         LOG.debug("getInternetvpnUuidBoundToSubnetRouter for subnetUuid {}", subnetUuid.getValue());
@@ -1652,7 +1573,7 @@ public class NeutronvpnUtils {
      * @param extNet Provider Network, which has a port attached as external network gateway to router
      * @return a list of Private Subnetmap Ids of the router with external network gateway
      */
-    public @Nonnull List<Uuid> getPrivateSubnetsToExport(@Nonnull Network extNet, Uuid internetVpnId) {
+    public @NonNull List<Uuid> getPrivateSubnetsToExport(@NonNull Network extNet, Uuid internetVpnId) {
         List<Uuid> subList = new ArrayList<>();
         List<Uuid> rtrList = new ArrayList<>();
         if (internetVpnId != null) {
@@ -1678,19 +1599,26 @@ public class NeutronvpnUtils {
                           router.getUuid().getValue(), extNet.getUuid().getValue());
                 continue;
             }
-            subList.addAll(getSubnetsforVpn(rtrId));
+            subList.addAll(getNeutronRouterSubnetIds(rtrId));
         }
         return subList;
     }
 
-    public void updateVpnInstanceWithFallback(Uuid vpnName, boolean add) {
+    public void updateVpnInstanceWithFallback(Uuid routerId, Uuid vpnName, boolean add) {
         VpnInstanceOpDataEntry vpnInstanceOpDataEntry = getVpnInstanceOpDataEntryFromVpnId(vpnName.getValue());
         if (vpnInstanceOpDataEntry == null) {
             LOG.error("updateVpnInstanceWithFallback: vpnInstanceOpDataEntry not found for vpn {}", vpnName);
             return;
         }
-        Long internetBgpVpnId = vpnInstanceOpDataEntry.getVpnId();
-        List<Uuid> routerIds = getRouterIdListforVpn(vpnName);
+        Long internetBgpVpnId = vpnInstanceOpDataEntry.getVpnId().toJava();
+        List<Uuid> routerIds = new ArrayList<>();
+        //Handle router specific V6 internet fallback flow else handle all V6 external routers
+        if (routerId != null) {
+            routerIds.add(routerId);
+        } else {
+            //This block will execute for ext-nw to Internet VPN association/disassociation event.
+            routerIds = getRouterIdListforVpn(vpnName);
+        }
         if (routerIds == null || routerIds.isEmpty()) {
             LOG.error("updateVpnInstanceWithFallback: router not found for vpn {}", vpnName);
             return;
@@ -1699,12 +1627,12 @@ public class NeutronvpnUtils {
             if (rtrId == null) {
                 continue;
             }
-            List<BigInteger> dpnIds = getDpnsForRouter(rtrId.getValue());
+            List<Uint64> dpnIds = getDpnsForRouter(rtrId.getValue());
             if (dpnIds.isEmpty()) {
                 continue;
             }
             VpnInstanceOpDataEntry vpnOpDataEntry = getVpnInstanceOpDataEntryFromVpnId(rtrId.getValue());
-            Long routerIdAsLong = vpnOpDataEntry.getVpnId();
+            Long routerIdAsLong = vpnOpDataEntry.getVpnId().toJava();
             long vpnId;
             Uuid rtrVpnId = getVpnForRouter(rtrId, true);
             if (rtrVpnId == null) {
@@ -1713,25 +1641,31 @@ public class NeutronvpnUtils {
             } else {
                 vpnId = getVpnId(rtrVpnId.getValue());
             }
-            for (BigInteger dpnId : dpnIds) {
+            for (Uint64 dpnId : dpnIds) {
                 if (add) {
-                    ipV6InternetDefRt.installDefaultRoute(dpnId, internetBgpVpnId, vpnId);
+                    LoggingFutures.addErrorLogging(
+                        txRunner.callWithNewWriteOnlyTransactionAndSubmit(Datastore.CONFIGURATION,
+                            tx -> ipV6InternetDefRt.installDefaultRoute(tx, dpnId, rtrId.getValue(),
+                                internetBgpVpnId, vpnId)), LOG, "Error adding default route");
                 } else {
-                    ipV6InternetDefRt.removeDefaultRoute(dpnId, internetBgpVpnId, vpnId);
+                    LoggingFutures.addErrorLogging(
+                        txRunner.callWithNewReadWriteTransactionAndSubmit(Datastore.CONFIGURATION,
+                            tx -> ipV6InternetDefRt.removeDefaultRoute(tx, dpnId, rtrId.getValue(),
+                                internetBgpVpnId, vpnId)), LOG,
+                        "Error removing default route");
                 }
             }
         }
     }
 
-    public void updateVpnInstanceOpWithType(VpnInstanceOpDataEntry.BgpvpnType choice, @Nonnull Uuid vpn) {
+    public void updateVpnInstanceOpWithType(VpnInstanceOpDataEntry.BgpvpnType choice, @NonNull Uuid vpn) {
         String primaryRd = getVpnRd(vpn.getValue());
         if (primaryRd == null) {
             LOG.debug("updateVpnInstanceOpWithType: Update BgpvpnType {} for {}."
                     + "Primary RD not found", choice, vpn.getValue());
             return;
         }
-        InstanceIdentifier<VpnInstanceOpDataEntry> id = InstanceIdentifier.builder(VpnInstanceOpData.class)
-              .child(VpnInstanceOpDataEntry.class, new VpnInstanceOpDataEntryKey(primaryRd)).build();
+        InstanceIdentifier<VpnInstanceOpDataEntry> id = getVpnOpDataIdentifier(primaryRd);
 
         Optional<VpnInstanceOpDataEntry> vpnInstanceOpDataEntryOptional =
             read(LogicalDatastoreType.OPERATIONAL, id);
@@ -1754,54 +1688,6 @@ public class NeutronvpnUtils {
         }), LOG, "Error updating VPN instance op {} with type {}", vpn, choice);
     }
 
-    public List<Uuid> getAssociateRouterInputRouterIdsListUuid(List<RouterIds> routerIds) {
-        if (routerIds == null) {
-            return Collections.emptyList();
-        }
-        return routerIds.stream().map(
-            routerId -> routerId.getRouterId()).collect(Collectors.toList());
-    }
-
-    public List<Uuid> getDisassociateRouterInputRouterIdsListUuid(List<RouterIds> routerIds) {
-        if (routerIds == null) {
-            return Collections.emptyList();
-        }
-        return routerIds.stream().map(
-            routerId -> routerId.getRouterId()).collect(Collectors.toList());
-    }
-
-    public RouterIds getvpnMapRouterIds(Uuid routerId) {
-        return new RouterIdsBuilder().setRouterId(routerId).build();
-    }
-
-    public void removeVpnMapRouterIdsFromList(Uuid routerId, List<RouterIds> vpnRouterIds) {
-        Iterator<RouterIds> vpnRouterIdIter = vpnRouterIds.iterator();
-        while (vpnRouterIdIter.hasNext()) {
-            RouterIds vpnRouterId = vpnRouterIdIter.next();
-            if (vpnRouterId.getRouterId().getValue().equals(routerId.getValue())) {
-                vpnRouterIdIter.remove();
-                return;
-            }
-        }
-        return;
-    }
-
-    public boolean vpnMapRouterIdsContainsRouterId(Uuid routerId, List<RouterIds> vpnRouterIds) {
-        if (routerId == null) {
-            return false;
-        }
-        return vpnRouterIds.stream().anyMatch(vpnRouterId ->
-              vpnRouterId.getRouterId().getValue().equals(routerId.getValue()));
-    }
-
-    public List<Uuid> getVpnInstanceRouterIdsListUuid(List<RouterIds> routerIds) {
-        if (routerIds == null) {
-            return Collections.emptyList();
-        }
-        return routerIds.stream().map(
-            routerId -> routerId.getRouterId()).collect(Collectors.toList());
-    }
-
     public static RouterIds getvpnInstanceRouterIds(Uuid routerId) {
         return new RouterIdsBuilder().setRouterId(routerId).build();
     }
@@ -1815,47 +1701,22 @@ public class NeutronvpnUtils {
         return listRouterIds;
     }
 
-    @Nonnull
-    public List<BigInteger> getDpnsForRouter(String routerUuid) {
+    @NonNull
+    public List<Uint64> getDpnsForRouter(String routerUuid) {
         InstanceIdentifier id = InstanceIdentifier.builder(NeutronRouterDpns.class)
             .child(RouterDpnList.class, new RouterDpnListKey(routerUuid)).build();
         Optional<RouterDpnList> routerDpnListData =
                 SingleTransactionDataBroker.syncReadOptionalAndTreatReadFailedExceptionAsAbsentOptional(dataBroker,
                         LogicalDatastoreType.OPERATIONAL, id);
-        List<BigInteger> dpns = new ArrayList<>();
+        List<Uint64> dpns = new ArrayList<>();
         if (routerDpnListData.isPresent()) {
-            for (DpnVpninterfacesList dpnVpnInterface : requireNonNullElse(
-                    routerDpnListData.get().getDpnVpninterfacesList(), Collections.<DpnVpninterfacesList>emptyList())) {
+            for (DpnVpninterfacesList dpnVpnInterface : routerDpnListData.get().nonnullDpnVpninterfacesList()) {
                 dpns.add(dpnVpnInterface.getDpnId());
             }
         }
         return dpns;
     }
 
-    @Nullable
-    public List<Uuid> getRouterIdsfromVpnInstance(String vpnName) {
-        // returns only router, attached to IPv4 networks
-        InstanceIdentifier<VpnMap> vpnMapIdentifier = InstanceIdentifier.builder(VpnMaps.class)
-            .child(VpnMap.class, new VpnMapKey(new Uuid(vpnName))).build();
-        Optional<VpnMap> optionalVpnMap = SingleTransactionDataBroker
-                .syncReadOptionalAndTreatReadFailedExceptionAsAbsentOptional(dataBroker,
-                        LogicalDatastoreType.CONFIGURATION, vpnMapIdentifier);
-        if (!optionalVpnMap.isPresent()) {
-            LOG.error("getRouterIdsfromVpnInstance : Router not found for vpn : {}", vpnName);
-            return null;
-        }
-        List<Uuid> rtrIds = optionalVpnMap.get().getRouterIds().stream().map(routerIds -> routerIds.getRouterId())
-                .collect(Collectors.toList());
-        return rtrIds;
-
-    }
-
-    public InstanceIdentifier<Router> buildNeutronRouterIdentifier(Uuid routerUuid) {
-        InstanceIdentifier<Router> routerInstanceIdentifier = InstanceIdentifier.create(Neutron.class)
-             .child(Routers.class).child(Router.class, new RouterKey(routerUuid));
-        return routerInstanceIdentifier;
-    }
-
     @Nullable
     List<Subnetmap> getSubnetmapListFromNetworkId(Uuid networkId) {
         List<Uuid> subnetIdList = getSubnetIdsFromNetworkId(networkId);
@@ -1882,8 +1743,69 @@ public class NeutronvpnUtils {
         InstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn
                 .instance.to.vpn.id.VpnInstance> id = getVpnInstanceToVpnIdIdentifier(vpnName);
         return SingleTransactionDataBroker.syncReadOptionalAndTreatReadFailedExceptionAsAbsentOptional(dataBroker,
-                LogicalDatastoreType.CONFIGURATION, id).toJavaUtil().map(
+                LogicalDatastoreType.CONFIGURATION, id).map(
                 org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.instance.to.vpn.id
-                        .VpnInstance::getVpnId).orElse(null);
+                        .VpnInstance::getVpnId).orElse(null).toJava();
+    }
+
+    protected boolean isV6SubnetPartOfRouter(Uuid routerId) {
+        List<Subnetmap> subnetList = getNeutronRouterSubnetMapList(routerId);
+        for (Subnetmap sm : subnetList) {
+            if (sm == null) {
+                continue;
+            }
+            IpVersionChoice ipVers = getIpVersionFromString(sm.getSubnetIp());
+            //skip further subnet processing once found first V6 subnet for the router
+            if (ipVers.isIpVersionChosen(IpVersionChoice.IPV6)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    public <T extends DataObject> void asyncReadAndExecute(final LogicalDatastoreType datastoreType,
+                                                           final InstanceIdentifier<T> iid, final String jobKey,
+                                                           final Function<Optional<T>, Void> function) {
+        jobCoordinator.enqueueJob(jobKey, () -> {
+            SettableFuture<Optional<T>> settableFuture = SettableFuture.create();
+            List futures = Collections.singletonList(settableFuture);
+            try (ReadTransaction tx = dataBroker.newReadOnlyTransaction()) {
+                Futures.addCallback(tx.read(datastoreType, iid),
+                        new SettableFutureCallback<Optional<T>>(settableFuture) {
+                            @Override
+                            public void onSuccess(Optional<T> data) {
+                                function.apply(data);
+                                super.onSuccess(data);
+                            }
+                        }, MoreExecutors.directExecutor());
+
+                return futures;
+            }
+        }, JOB_MAX_RETRIES);
+    }
+
+    private static InstanceIdentifier<VpnMap> vpnMapIdentifier(Uuid uuid) {
+        return VPN_MAPS_IID.child(VpnMap.class, new VpnMapKey(uuid));
+    }
+
+    private class SettableFutureCallback<T> implements FutureCallback<T> {
+
+        private final SettableFuture<T> settableFuture;
+
+        SettableFutureCallback(SettableFuture<T> settableFuture) {
+            this.settableFuture = settableFuture;
+        }
+
+        @Override
+        public void onSuccess(T objT) {
+            settableFuture.set(objT);
+        }
+
+        @Override
+        public void onFailure(Throwable throwable) {
+            settableFuture.setException(throwable);
+        }
     }
 }
+