[ntp:questions] NTP timestamps

Chuck Swiger cswiger at mac.com
Tue May 25 21:47:53 UTC 2010


Hi--

On May 25, 2010, at 2:20 PM, Ray wrote:
> Thanks again.  tcpdump shows the content of the NTP packet.

Yes.

> The destination (or return) timestamp is not in there. It is stamped by the NTP daemon itself.

Right-- if you are running tcpdump on the machine running NTPd, then the timestamp of when tcpdump sees the packet is probably going to be a little before the exact time when NTPd will see it.  Otherwise, if you are snooping traffic in the middle, you just see the timestamps which are present in the packet.

> I am also looking for a Linux version so that I can monitor a stratum-1 server, against a remote server, to see network delays.
> Any ideas would be appreciated.

Are you looking for tracking the offset against some remote server and graphing it like the NTP pool does, for example:

  http://www.pool.ntp.org/scores/208.75.88.4

...?

Regards,
-- 
-Chuck




More information about the questions mailing list