strange DNS issue

[telecotek1]

I'm leaning towards DNS but to be honest im not really sure thats what it is. I have Hyper-V guest running on a DL380 gen 9 and it loses connectivity with the internet randomly. the only way to resolve the issue is to reboot the server. I;ve tried rebuilding the tcp stack i've tried to blow away the network adapter and rebuild it. This happen to be a machine that is on a different vlan then the rest of my servers so this particular server is honoring a vlan tag.

When this happens...

I can ping the domain controller (DNS server), google.com, default gateway open a web browser and try to serf the web and nothing. Monitroing software for that guest goes offline and my availability numbers are looking really crappy because of this guest.

 

[telecotek1]

update.

I found this error in the event log

The Event ID: 4231
A request to allocate an ephemeral port number from the global TCP port space has failed due to all such ports being in use.

and will be applying this hot fix

https://support.microsoft.com/en-us...ter-issues-occur-when-tcp-ephemeral-ports-are