[ntp:questions] Why does ntp keep changing my conf file?

Rob nomail at example.com
Thu Sep 16 20:04:30 UTC 2010


Daniel Havey <dhavey at yahoo.com> wrote:
> Did you mean between my testbed and ntp.aero.org/dns.aero.org (the servers in my ntp.conf file)?  There could be a firewall there but then I shouldn't be able to do this:
> [dhavey at node0 ~]$ sudo ntpdate ntp.aero.org
> 16 Sep 11:31:08 ntpdate[13121]: adjust time server 130.221.24.100 offset 0.017606 sec
>
> I don't think it is a firewall issue.

When you do "ntpdate" it sends from a high port number to port 123
on the timeserver, and the timeserver replies from port 123 to your
high port number.

When you use "ntpd" it sends from port 123 to port 123 on your timeserver,
which replies back to port 123.

When your firewall or some other firewall in your network blocks traffic
to port 123 or to all low portnumbers, you will find that ntpdate works
ok but ntpd won't.




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