Hi experts,

we are running several SLES 11 SP3 Enterprise Servers on VMs and they are all showing the same sitution:

- System startup - OK
- Connect to server with SSH Secure shell - Fail
- Ping Server - OK
- Connect to server with SSH Secure shell - OK
- Working on Server using SSH for several minutes/hours ... - OK
- Trying to establish a new SSH connection after a few minutes - Fail
- Ping Server - OK
- Establish new SSH connection - OK

...

This isn't only a SSH-Problem. On this machine a small SAP-System is installed which is showing
the same sitution when trying to connect using SAPGui.

- Try to connect - fail
- Ping Server - OK
- Try to connect - OK
- Working for several hours - OK
- Trying to open a new SAPGui-Session after a few minutes - Fail
- Ping Server - OK
- New SAPGui-Session - OK

...


Working on the Machine using the Console of the VSphere-Client works without any problems.
All mounted network-drives etc are available without disconnects.

All machines have static IP adresses. IPv6 and the Linux Firewall is disabled. VMWare tools are also installed.

The network-connection of the ESX-Server hosting the systems is OK.
There are a few SLES10 servers on the same ESX working without any problems.

Any ideas what can cause these kind of problems ?


Thanks for your help