Just wondering if anyone has run into problems where their netware server will for no obvious reason just lose all or almost all network connectivity?

Seems like almost weekly on our main Groupwise server and we have another netware server hosting a secondary domain that seems to have this same problem about once a month. Both servers are Netware 6.5 SP7 and running groupwise 8.0.2. The server with the secondary domain is running netware on ESXi 4.

When the server is having these issues I cannot ping anything but the servers ip's from the server and from outside the server pinging the server ip's is very hit and miss, but mostly miss.

Anyone have any thoughts or troubleshooting ideas I could look at trying to figure out the cause of this issue? Oh and another thing is I notice groupwise messenger start disconnecting and reconnecting usually a few hours before all connectivity is lost.