autofs and nfs4 no longer connect

[Robert G. (Doc) Savage]

I set up autofs and nfs4 between F12/F13 and RHEL5.5 so all my laptops
could access a 1TB general purpose storage array mounted to /pub on a
server named lion. That's where I maintain all my repo mirrors and other
archives. The exported array was accessible from any local node:

        # cat /etc/exports
        /pub    192.168.1.0/24(rw)
        
        # exportfs
        /pub    192.168.1.0/24
        
Suddenly, about two weeks ago, I noticed none of my F12/F13 laptops were
able to connect to /net/lion/pub. I can't find anything wrong on the
server 'lion':

        # service autofs status
        automount (pid 3865) is running...
        
        # service portmap status
        portmap (pid 3593) is running...
        
But now on any client...

        # ls -l /net/lion/
        ls: cannot access /net/lion/: No such file or directory
        
This was supposed to "just work", but now doesn't.

Ideas? Suggestions?

--Doc Savage
  Fairview Heights, IL