[ntp:questions] NTP Sync Problem

Richard B. gilbert rgilbert88 at comcast.net
Mon Mar 5 01:10:37 UTC 2007

Ron C. wrote:
> I'm using Netopia routers on Covad (model 4622 on T1 and 4652 on DSL).  They have built-in NTP clock syncronization with two pre-programmed servers. Although the routers work fine, I have never been able to get the sync function working. Left to themselves, they each gain 8 minutes per day so it would be nice to be able to use the sync feature.  I know that UDP port 123 should be open in both directions and as a test I turned off the firewall completely.  The device event log gives this error message "NTP: cannot SEND packet to server <ip address>" every 3 minutes, alternating between the primary and secondary NTP servers. Besides the two pre-set servers ( and I've tried several public servers from the NIST list.  BTW, I have no problem syncing computers on the same local network using a Windows-based NIST time client.  Only the router itself won't sync and gives that error message.

I don't think that there is any hope of getting those routers to 
synchronize with NTP.  NTP generally does not cope with clock frequency 
errors in excess of 500 parts per million or about 43 seconds per day. 
(This is the maximum rate at which most kernels can (or will) slew the 
system clock.)

Talk to the manufacturer about repair under warranty (if they are still 
under warranty).  If not try a better vendor!  Cisco Systems sells top 
quality stuff!  At top prices, of course! :-)

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