Hyper-V virtual servers losing connectivity to other random servers

[mitchell1981]

Sorry, this is one that's been causing me problems for a while, but it's difficult to explain, and therefore difficult to Google.

 

We have a Hyper-V cluster of seven nodes. Every now and then, one of the virtual servers will suddenly decide it cannot see one of the other virtual servers (on another host). The two servers will not be able to ping each other at all. All other communication on the servers works fine. The cluster logs no errors.

 

It seems like a problem with the host, but both servers can ping all the other servers on the other host. It's only the direct connection between the servers that is lost. Rebooting the servers does not fix it. However, migrating one of the servers to another host immediately makes it work again.

 

As you can imagine, this can cause serious issues, when for example, the Skype for Business Server loses contact with the Exchange server. It's easy to fix once you identify the problem, but I really want to stop it happening.

 

Anyone experienced anything similar?

 

For info, the hosts are HP Blades BL460c. The network adapters in the Hosts are: HP FlexFabrix 10Gb 2-port 554FLB