I have a server running windows server 2003 R2. This server is also running Exchange 2007 SP1. The server runs fine for about 16 hours then looses some of it's communications abilities.
It can still communicate with other servers on our network. I can ping it's default gateway and our VPN / firewall. I can run a tracert to google.com and it works.
Trying to use a web browser from this system fails as does any attempt to send email out.
When the system is in this state, simply rebooting it fixes the problem until it happens again.
I am not a guru at getting under the hood in Windows and diagnosing this kind of thing by looking at log entries. I believe that the issue is with Windows itself since other forms of communication are affected.
What I would like is a set of tests I can run in order to determine what is causing the blockage, then what I need to do to avoid it happening in the future.