Hi Everybody,
I am experiencing a strange issue with a Server 2012 R2 Hypervisor. There are two physical NICs teamed (one from on-board and one from expansion board), this team is assigned to a hyper-v virtual switch, there are four virtual network adapters assigned to the switch (Backend, Heartbeat, Management & CSV/Live Migration).
The server has been running without issue for months but, all of a sudden has started to lose connectivity to the Backend and Heartbeat. The loss of connection only occurs once VMs are hosted on the server and it doesn't happen immediately, it can take anywhere from 12 hours to several days.
There are no errors on the NICs or vNICs themselves and the configuration is intact. Once connectivity is lost to the Backend and Heartbeat, it remains that way and it seems the only solution so far is to reboot the server. Hardware diagnostics have been run and revealed no issues. There are no useful events in event viewer, the alerts relate to the loss of connection to the cluster as a result of connectivity being lost on the Backend and Heartbeat.
I have 6 other hypervisors with the same network configuration that are performing without issue so, I don't believe the problem is the configuration. The only difference is the hypervisor that has the problems is a Dell Poweredge R620 and the other 6 are Dell PowerEdge R610s.
Can anyone advise what might be the cause of these issues or, any event logging to enable that might help isolate where the issue lies.