Help with RHEL 5.0 Server as NTP server

[Scott R. Ehrlich]

I have an out-of-box RHEL 5.0 Server, unpatched, that I want to use as an NTP 
server.  It is in an isolated LAN.

An nmap scan of localhost shows 123/udp is open|filtered.

I tried sudo ntpdate from a CentOS 5 client to the server, but keep receiving 
strata too high.   Debug mode shows it tries to reach the server 4 times, then 
fails, saying no server is available.

I've manually set the time on both to be within seconds of each other, with 
same day, date, and year.

I've also tried ntpdate -u server and no luck.

I've verified throuvh chkconfig on client and server that iptables and 
ip6tables is not running, iptables -L and ip6tables -L show nothing, and I've 
performed a ps auwx to review all processees.   Nothing pointing to any kind of 
filtering.

What else might I be missing?  It serves NFS and SMB with no problem.

Thanks for any insights.

Scott