NIS problem

[Dan Nelson]

In the last episode (Oct 16), Adam Maloney said:
> In the last couple of days we have seen a lot of messages like the
> one below appearing in /var/log/messages:
> 
> Oct 13 06:14:58 xxxxx ypserv[45883]: access to master.passwd.byname denied -- client 1.2.3.4:3458 not privileged
> 
> This goes on for a number of minutes, and then fixes itself.
> 
> Obviously, the problem is that the NIS lookup request is coming from
> a non-priveleged (> 1024) port, and ypserv won't honor it.  What's
> not so obvious is why/how this is happening.
>
> I'm suspecting it's Sendmail, since the frequency of the message
> somewhat coincides with the rate of incoming mail on this box.  But I
> can't seem to find any clues on the web or usenet confirming this.  Has
> anyone seen this before, or know of a solution?

That message gets printed whenever a remote NIS client tries to access
master.passwd.* over a non-privileged port.  Only root should have
access to the master maps, so a remote process has to bind to a port <
1024 before doing the lookup, to prove that it's root.  It looks like
for some reason you have a process that's running as root but is using
a port over 1024.  I can't see anyplace in the NIS client code that
binds the socket, though, so I must be looking in the wrong place.  It
has to work, or else you wouldn't be able to log in using NIS at all.

-- 
	Dan Nelson
	dnelson at allantgroup.com