[c-nsp] NTP synchronization problems C2801

[Rodney Dunn]

Can you try the iburst option to see if it changes it?

http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_10.html#wp1102197

I don't see how going back to 24T would change it as it has v4 there 
too...unless there was something later that made it even worse.

Rodney



On 6/30/10 5:25 PM, Peter Rathlev wrote:
> On Wed, 2010-06-30 at 14:12 -0400, Rodney Dunn wrote:
>> I'm not a NTP expert but I know there were some issues when it went to
>> v4 regarding sync times, etc...
>>
>> One of them was:
>>
>> CSCte91471    NTP v4 takes several hours to sync when multiple servers
>> are configured
>>
>>  From looking at the source code that fix doesn't appear to be in
>> 15.0(1)M2.
>>
>> You may want to try it with the next rebuild when it comes out.
>
> That sounds just like it. I can see the 15.1(1)T also has the same bug,
> so I guess there's no point in trying that one.
>
> I've had an expect script run "show ntp status" every five minutes on
> the two devices the last 5-6 hours, and if I extrapolate linearly
> (R^2=0.76 though) the one running 15.0(1)M2 will be synchronized in
> around 11 hours, from an offset of ~15 ms now.
>
> The bug description says "... after few hours.", but this one will have
> taken nearly 36 hours if the linear extrapolation is correct.
>
> Tomorrow I will try to downgrade to 12.4(24)T3 to make sure it isn't
> hardware related. The one running 12.4(24)T3 now has the past 5 hours
> never exceeded 1 usec offset according to "show ntp status".
>