[ntp:questions] Re: ntp server behind ADSL alcatel speedtouch 510 firewall not responding.
ronan at noc.ulcc.ac.uk
Tue Dec 21 11:27:45 UTC 2004
Remko Bolt <marem at concepts.nl> wrote:
> I opened up ports udp/123 and tcp/123 on the alcatel and forward them to
> the ntp-server. I have similar setup's for http and ssh which work fine.
> Problem: The ntp-server is not responding to queries from the outside
> world. It is located at ntp.cluebox.org have a look.
> If I telnet to :80 I get a http welcome etc. This is not so with ntp.
NTP doesn't use TCP, so you can't telnet to port 123.
You can remove tcp/123 from your firewall permissions.
> Is there an easy way to check if a server is accepting connections?
If you have shell access to an external host with the NTP software
ntpdate -q ntp.cluebox.org.
ntpq -p ntp.cluebox.org.
and see what you get.
> Can anybody confirm that it `should' work this way with the ports set up?
> Any other thoughts?
Depends on what is in your ntp.conf, as Harlan said.
Ronan Flood <R.Flood at noc.ulcc.ac.uk>
working for but not speaking for
Network Services, University of London Computer Centre
(which means: don't bother ULCC if I've said something you don't like)
More information about the questions