Re: ntpd on a NAT gateway seems to do nothing

On 2007-Jul-24 16:00:08 +0100, Pete French <petefrench@xxxxxxxxxxxxxxxx> wrote:
at least I cannot see anything wrong). I would assume that ntpdate
also uses UDP - and using that I can see all these servers ?

Yes it does. The major difference is that ntpd will use a source
port of 123 whilst ntpdate will use a dynamic source port.

Is it possible that your NAT rules are interfering with ntpd using
port 123? Can you check that ntpd is binding to port 123 (using
lsof or netstat+fstat). As well as tcpdump'ing the NTP traffic,
you might like to ktrace ntpd and verify that incoming packets
are actually arriving there.

If your NAT box is not busy, you might be able to enable logging on
som relevant rules and see what your firewall is actually doing
with the packets.

--
Peter Jeremy

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