Help: NIS & NFS Server Randomly Stops Working

["Matthews, John" <JMatthews LIO AACISD com>]

Hello,

	I have a NIS & NFS server running a stock Red Hat 6.1 distribution.
The server is beginning to stop working more and more frequently now.  NIS
used to mess up once or twice a week, but now it appears to go down two to
three times a day.  I've seen the problem sometimes be related to
"portmapper" not functioning, other times I see that nfsd appears to
disappear, or ypserv will be running, but it won't be working. 
	
	Does anyone have any idea what could be causing this sort of erratic
behavior?  I've looked through the logs, but I haven't seen anything
pointing to a problem.  The services appear to just die without warning.
Are there known issues with NIS & NFS not working well on Red Hat 6.1?

	The server is beginning to see heavier usage now, so I guess that is
causing it to fail more often.

	Thanks in advance,
	John