On Wednesday 12 October 2011 03:43, the following was written:
Hi, This is a Centos 5.5 host with one xen guest. About 2 weeks ago, the host randomly lost network connection. By this I mean I could not connect to the services on it, or ping it. Also was the status of the guest. From serial console, I connected to the host, trying to see what happened. No clue (any error messages) in messages or dmesg. ifdown/ifup the interface did not help, either. Only rebooting was my only choice. Searching through Google, I got the information that some other guys met similar problem, and resolved by setting stp on with the bridge interface. I set it, too. And the problem still occurs. Any idea what I should check now?
I am no expert but it sounds like you might be in the early stages of hardware failure.
Next time this system stop responding check the following:
1. System interface state 2. Connected switch interface
If the switch shows down but the system shows up I wold start by replacing the NIC on the system.