Description of problem:

When a kubevirt vm is using primary udn layer2 network and opening a connection towards and external service, after live migration the traffic is going to egress over different node so src-ip changes breaking the 5 tuple tcp connections and making server send a RST since src-ip has changed.

Version-Release number of selected component (if applicable): 4.18

How reproducible: Always

Steps to Reproduce:

1. Create an external container with something like "iperf3 -s -B external ip"

2. Create a VM with layer2 primary UDN running "iperf3 -c external ip -t 0"

3. Live migrate the VM

Actual results:

The client receive a TCP RST and iperf3 client breaks with "peer reset"

Expected results:

Tcp connection is not broken

Additional info:

At other virt environments like openstack this is done using the "floating ip" feature from OVN perspective they use "dnat_and_snat" but that do not work currently with interconnect, it may work with future transit router work.

Affected Platforms: internal CI failuter