[ntp:questions] Synchronizing to LOCAL(0): Startup time

Bert Gøtterup Petersen BUP at bang-olufsen.dk
Fri Oct 12 12:01:33 UTC 2007


Dear all

I am trying to use NTP to synchronize embedded audio-video products 
(running Linux).
Once the products are synchronized everything is working very well, but I 
have a problem at start up.
I use a set of products to work as peers, as can be see in the example of 
an ntp.config file:

peer 192.168.1.80  iburst burst prefer minpoll 4 maxpoll 4 prefer
peer 192.168.1.98  iburst burst prefer minpoll 4 maxpoll 4 prefer
peer 192.168.1.162 iburst burst prefer minpoll 4 maxpoll 4
server 127.127.1.0 iburst # local clock (LCL)
fudge 127.127.1.0 stratum 6 # LCL is unsynchronized flag1 0 flag2 0 flag3 
0 flag4 0 stratum 0

In addition a set of products are used which are only NTP clients. 
As can be seen I use the local crystal as fall back, and this is were the 
problem arises.
When the first of the peers is started it takes about 4 minutes before is 
has synchronized with to its local crystal and further 3 minutes before a 
clients can see that the server is in synch, i.e. starting its synch 
process.

 8 Oct 15:28:16 ntpd[6970]: system event 'event_restart' (0x01) status 
'sync_alarm, sync_unspec, 1 event, event_unspec' (0xc010)
 8 Oct 15:28:17 ntpd[6970]: peer LOCAL(0) event 'event_reach' (0x84) 
status 'unreach, conf, 1 event, event_reach' (0x8014)
 8 Oct 15:31:27 ntpd[6970]: system event 'event_peer/strat_chg' (0x04) 
status 'sync_alarm, sync_local_proto, 2 events, event_restart' (0xc521)
 8 Oct 15:31:27 ntpd[6970]: synchronized to LOCAL(0), stratum 10
 8 Oct 15:31:27 ntpd[6970]: kernel time sync disabled 0041
 8 Oct 15:31:27 ntpd[6970]: system event 'event_sync_chg' (0x03) status 
'leap_none, sync_local_proto, 3 events, event_peer/strat_chg' (0x534)
 8 Oct 15:31:27 ntpd[6970]: system event 'event_peer/strat_chg' (0x04) 
status 'leap_none, sync_local_proto, 4 events, event_sync_chg' (0x543)
 8 Oct 15:32:33 ntpd[6970]: kernel time sync enabled 0001

How can I get the initial synchronization to a local crystal down from 
several minutes to a few seconds?

Thanks in advance

Bert Petersen
Bang & Olufsen A/S



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