[ntp:questions] ntpdate works, but ntpd doesn't (reach = 0)
martin.burnicki at meinberg.de
Wed Feb 4 09:02:02 UTC 2009
sorry for the late reply, I've been offline for a few days.
Danny Mayer wrote:
> Martin Burnicki wrote:
>> Lizvette Malave wrote:
>>> ntpdate timeServer (without the -u option) works too.
>>> Is there a way to make the ntpd use a different port?
>> If "ntpdate timeServer" works then this does not seem to be a firewall
> On the contrary. Some people block outgoing packets from privileged
> ports like 123/UDP. ntpdate uses a non-privileged port and is therefore
> not blocked.
What you wrote above about port usage by ntpdate is not correct and you
should know this.
By default ntpdate sends and receives packets via port 123/UDP. It *only*
sends via an unprivileged port if either -q (query only), -u (unpriv.
port), or -d (debug) is given on the command line.
This is also the reason why ntpdate by default refuses to work if ntpd is
already running, which is AFAIK by design.
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