[ntp:questions] My ntpd stopped working

Steve Kostecke kostecke at ntp.org
Mon Sep 17 14:43:26 UTC 2007


On 2007-09-17, rasmus <rasmusaa at gmail.com> wrote:

> hmm, I played a bit around with this and other stuff w/o getting
> anywhere. So I went to do other stuff and basically haven't touched
> anything for a couple of days. So looking at this graph,
> http://www.pool.ntp.org/scores/90.184.3.208, of my servers pool
> performance is really puzzling me. Can anyone offer me a clue? :)

The red areas in the colored band the top of the upper graph on your
pool stats page indicates when your server is either unreachable or
significantly wrong. It appears that your server is "in the red" most of
the time.

As a test I added your server to one of my ntpds. Your server has
remained in .INIT. for an extended period of time and shows no signs of
being reachable.

nmap shows this:

| # nmap -sU -p 123 90.184.3.208
| 
| Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-09-17 09:51 EDT
| Interesting ports on 3404ds2-brh.0.fullrate.dk (90.184.3.208):
| PORT    STATE         SERVICE
| 123/udp open|filtered ntp
| 
| Nmap finished: 1 IP address (1 host up) scanned in 8.517 seconds

Open means that an application on the target machine is listening for
connections/packets on that port. Filtered means that a firewall,
filter, or other network obstacle is blocking the port so that Nmap
cannot tell whether it is open or closed.

It should also be noted that queries with ntpq to 90.184.3.208 always
time out.

Are you sure that your firewall is not blocking port 123/UDP?

If you need to port forward 123/UDP to a machine behind your firewall,
are you sure that this is actually happening?

Is it possible that connections to your port 123/UDP are going to a
locked down ntpd on your firewall?

Does 'ntdpc -c monlist 90.184.3.208' show anything? You ought to see my
IP address in there...

Are you sure that ntpd is not using another configuration file?

Did you know that ...

* You may get a "remote view" of the ntpd at the IP address you are
"browsing from" by visiting http://support.ntp.org/ntpd.php

* You may view information about an ntpd at any arbitrary address by
visiting http://www.vanheusden.com/query_ntp.php

-- 
Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/




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