I am having some strange issues when VM's migrate from a 5.5 host to a 5.0 host where the VM loses network connectivity once the vMotion completes on the 5.0 host. The only way I can fix it is manually moving it back to a 5.5 host. The cluster is managed by vCenter 5.5 latest release. I also have everything on a single vDS switch in 5.0.0 compatibility mode to accommodate all of our hosts. I guess it gets strange when I noticed that other VM's on the same troubled host and same vmnic (same port group as well) are fine and never loses connectivity. So I think the migration actually triggers this to occur, not for VMs that already resided on the host. This only happens on our 5.0.0 hosts so far. Anyone ever heard of something like this? I also noticed a weird bug once I migrated everything over to vDS where the old Standard switch networks still shows under 'Networking' listing some VM's. When I check the VM's and go to edit settings, it then shows the correct distributed port group and not the standard port group that it use to be on. Just weird.
Our updated hosts are running 5.5 (1746018)
Our hosts having these issues are running 5.0 (623860)
I confirmed I can recreate the issue by migrating a VM to 5.0 from a 5.5 host. If I then go into edit settings and change the distributed port group to something random, and then change it back to what it was just on, it works fine. Pretty crazy.
I only happens with a VM? Happen with all the VMs?
That version vmnic have VMs?
The Esxi are the latest level of firmware / drivers?
Look at this KB:
It has happened for every VM we've tried so far. I just tried upgrading VM tools on one of the VM's and it still had the issue. So far the only fix seems to be upgrading the hosts to the latest version of 5.5.