I currently have a 2 node OVM 3.1.1 cluster, fully patched, and have noticed that I lose network connectivity while performing a live migration. I have separate networks for VM's and for live migration. I am new to OVM so I do not know if this is typical or not. It appears that every time I migrate a VM, the client will lose connectivity to the network for anywhere from 5 - 20 seconds.
Are you talking about lost pings to the guest VM that is live migrated? If yes, that I'd suppose that to be normal behaviour, since there has to be some interruption, once the memory contents is finally synchronized between the source and the target VM server.
Depending on much RAM is used by the running VM and the speed of your network, this "outage" might vary in time, but there will surely always be some time span where pings to the VM that is being live migrated get lost.
Like budachst said.... you're going to lose a few pings. This normal. I've never seen more than about 5 or 10 sec cut time. Its usually smaller if you have everything on the same switch. The time it takes to update the layer 2 mac table on the switching fabric can be several seconds. This not something specifically related to Oracle VM.