How come I get 'no server suitable for synchronization found' from my NTP client when the server is returning a valid NTP response to the client? · 4 May 2008, 12:44

This is one I hadn’t seen before last week. On our Solaris 9 clients, running

ntpdate -d -u ip.of.server

Kept on returning

no server suitable for synchronization found

even though the debug mode showed UDP responses coming back from the server. The server in question runs using UDP / unicast mode.

We used snoop to look at the NTP response

snoop -v -v port 123

(use -v -v to get the protocol decode output), and saw these suspicious field/value pairs:

NTP: Leap: 0x03 - clock unsynchronized
NTP: Reference clock: INIT
NTP: Reference time: 0x00000000.00000000

There were other headers, but they did not indicate problems. 0×03 in the Leap field, the INIT state, and a reference time of 0×00 indicated that the NTP server was not properly initialized / configured properly. Further investigation revealed that indeed, this was the case, the Sidewinder / G2 NTP server was not properly configured.

— Max Schubert



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