Topology:
=========
Two OVS switches are connected to Genius Carbon controller running karaf.

Description:
============
Creating VxLan ITM between two OVS switches first time works fine. When we delete and re-create VxLAN tunnel then interfaces are flapping.

Steps to repro this issue:
==========================
1. Run distribution ODL controller (See "Running Karaf" section below)

2. Config OVS1 and OVS2 (See below "OVS-1 Configs" & "OVS-2 Configs" section below).

3. Create ITM tunnel using curl command (See "Curl commands to create and delete ITM" section below). Verify/Ensure "tep:show-state", "tep:show" & "vxlan:show" output on ODL controller are as expected.

4. Delete ITM tunnel using curl command. Verify/Ensure "tep:show-state", "tep:show" & "vxlan:show" output on ODL controller are as expected.

5. Once again create ITM tunnel using curl command. Periodically (say every 5secs) execute tep:show-state" OR "vxlan:show" on ODL controller.

Observe: We see that tunnel interfaces are flapping (karaf logs are attached with this bug).

Running Karaf
=============
1. Download Carbon image from https://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/org/opendaylight/integration/distribution-karaf/0.6.0-SNAPSHOT/distribution-karaf-0.6.0-20170424.011734-5016.tar.gz
2. tar -zxvf distribution-karaf-0.6.0-20170424.011734-5016.tar.gz
3. Get into extracted directory
4. Run bin/karaf and issue "feature:install odl-genius-ui" on karaf prompt.
5. Enable interface trace log collection using "log:set TRACE org.opendaylight.genius.interfacemanager" on karaf prompt.

OVS-1 Configs
=============
sudo ovs-vsctl add-br BR1
sudo ovs-vsctl set bridge BR1 protocols=OpenFlow13
sudo ovs-vsctl set-controller BR1 tcp:10.164.225.106:6633
sudo ifconfig BR1 up
sudo ovs-vsctl set-manager tcp:10.164.225.106:6640
sudo ovs-vsctl show
sudo ovs-ofctl show BR1 -O Openflow13

OVS-2 Configs
=============
sudo ovs-vsctl add-br BR2
sudo ovs-vsctl set bridge BR2 protocols=OpenFlow13
sudo ovs-vsctl set-controller BR2 tcp:10.164.225.106:6633
sudo ifconfig BR2 up
sudo ovs-vsctl set-manager tcp:10.164.225.106:6640
sudo ovs-vsctl show
sudo ovs-ofctl show BR2 -O Openflow13

Curl commands to create and delete ITM
=======================================
curl -u admin:admin -X POST -H "Content-Type:application/json" -d @itm.body "http://10.164.225.106:8181/restconf/config/itm:transport-zones/" -v

curl -u admin:admin -X DELETE -H "Content-Type:application/json" -d @itm.body "http://10.164.225.106:8181/restconf/config/itm:transport-zones/" -v

itm.body
========
{
"transport-zone": [
{
"subnets": [
{
"gateway-ip": "0.0.0.0",
"prefix": "10.164.225.0/24",
"vlan-id": 0,
"vteps": [

,

]
}
],
"tunnel-type": "odl-interface:tunnel-type-vxlan",
"zone-name": "TZA"
}
]
}