Trying to setup an NFS/NIS pair of systems at work has been driving me nuts. All the HOWTO guides kept referencing an /etc/sysconfig/network file that is a directory on my systems. I guessed, correctly, that what they wanted in those files should go into the /etc/sysconfig/network/ifcfg-eth0. Everything else seemed pretty much straightforward, but connections would fail with the NIS client unable to even see the NIS server.
In my /var/log/messages, I saw
Jun 23 12:41:02 machinename ypserv[23456]: refused connect from x.x.x.x:35684 to procedure ypproc_domain_nonack (domainname,;0)
It turned out I needed to add to my /var/yp/securenets file. When I first opened it up, in only had 127.0.0.0. After I added a netmask for my subnet (255.255.0.0 x.x.0.0), things went much more smoothly.
And after all that, it turns out that the customer problem had nothing to do with NFS or NIS, it was a simple permissions issue of 755 vs 775. d’oh. If only they had sent the logs first, instead of last.