[[odl-ofp-test-provider-topoogy_test-provider]]
==== Topology : Notification

Currently, the openflowplugin has a test-provider that allows you to get
notifications for the topology related events like Link-Discovered ,
Link-Removed events.

===== Link Discovered Event : Testing

Run the controller by executing:

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cd openflowplugin/distribution/base/target/distributions-openflowplugin-base-0.0.1-SNAPSHOT-osgipackage/opendaylight
./run.sh
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Point your mininet to the controller by giving the parameters
--controller=remote,ip=. Once the controller is connected to the switch,
Link-Discovered event can be tested by initially configuring the
specific flows on the switch. For Link Discovered event either
table-miss flow or LLDP ether-type flow can be configured.

Configuring Table-Miss flow using OpenflowpluginTestCommandProvider

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addMDFlow Openflow:1 fTM
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as per this
OpenDaylight_OpenFlow_Plugin:Test_Provider#Flows_:_Test_Provider[link].
'fTM' is the table-miss scenario here.

Once the table-miss flow is configured through above command, we can see
the Link-Discovered event in the debug logs on the controller console.

Configuring LLDP ether-type flow using OpenflowpluginTestCommandProvider

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addMDFlow Openflow:1 0(table-id) f81
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You can confirm that they were created on the switch.

Once the LLDP ether-type flow is configured through above command, we
can see the Link-Discovered event in the debug logs on the controller
console.

===== Link Removed Event : Testing

Having configured either table-miss or lldp ether-type flow on switch,
once the switch is disconnected we see the Link-Removed event