network keep droping

[PP]

Izwan Mohd wrote:
> Hi,
> 
> I have being encountering a weird problem on my freebsd 6 , one of my remote
> machine being down frequently lately for no particular reason, when I go to
> the remote site to check then machine it was in good running condition but
> no network, it even can't ping the server on the same subnet, the only way
> to restore it back is by running:
> 
> route -n flush && /etc/netstart
> 
> but because it a remote machine it really troublesome to do that each time
> the machine is down, I resorted to use a crontab scripts to automatically
> run the previous command when it down, even tho that partial of the problem
> is solve I still need to know what causing it. can anyone could advise me
> where to start digging?? they is no any particular error in the log or dmseg
> when the machine dropped it connection so I'm stuck here don't know where to
> start, some help should clear something up for me
> 
> TQ

This sounds vaguely similar to what I've experienced myself with an 
onboard em0 on a Supermicro mainboard. NIC suddenly stopped working for 
no appearent reason. Believing the NIC was bad I throw in an extra NIC 
and ran the machine from that. But within a month a capacitor blew in 
the PSU and when I replaced the PSU the onboard NIC worked again. This 
scenario repeated 3 times in exactly the same way before I switched to 
another PSU brand and haven't had any problems since. In my case I 
couldn't get the NIC running with a simple flushing of the routes 
though. But if nothing has changed in the software on the machine you 
should probably start looking at the hardware.
/PP