[c-nsp] NTP not synchronizing

Velasquez Venegas Jaime Omar Jaime at ulima.edu.pe
Tue Sep 16 22:23:04 EDT 2008 

I kept working on this ntp issue.It's a fact that there's no packet
going out of the serial interface of the router even when NTP debugging
says "NTP xmit packet".NTP Server is reacheable from the router through
any protocol.
Did some attempts like swapping ntp server ,changing ntp
versions,changing ntp server software,adding ntp broadcast delay in the
router.Heck I even disabled ntp so I can get a different message other
than Clock is unsynchronized.
Last time I restarted the router I removed all the ntp configuration in
the hope that it recalculates "ntp clock-period" parameter as cisco
documentation states but it didn't so now it's working with the previous
clock-period parameter.

These are detailed outputs of ntp status commands:

R1>show ntp assoc de

<NTP.Server> configured, insane, invalid, unsynced, stratum 16
ref ID 0.0.0.0, time 00000000.00000000 (19:00:00.000 <City> Thu Dec 31
1899)
our mode client, peer mode unspec, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 0.000
delay 0.00 msec, offset 0.0000 msec, dispersion 16000.00
precision 2**5, version 3
org time 00000000.00000000 (19:00:00.000 <City> Thu Dec 31 1899)
rcv time 00000000.00000000 (19:00:00.000 <City> Thu Dec 31 1899)
xmt time CC7AC750.449B3CCC (19:01:20.267 <City> Tue Sep 16 2008)
filtdelay =     0.00    0.00    0.00    0.00    0.00    0.00    0.00
0.00
filtoffset =    0.00    0.00    0.00    0.00    0.00    0.00    0.00
0.00
filterror =  16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0
16000.0

R1>show ntp stat

Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 249.5901 Hz, actual freq is 249.5906 Hz, precision is
2**16
reference time is CC7553E4.FE3E6D2D (15:47:32.993 <City> Fri Sep 12
2008)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.02 msec, peer dispersion is 0.02 msec

I may try to restart it one more time before I suspect a faulty ntp
service.

-----Mensaje original-----
De: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] En nombre de Aaron R
Enviado el: Monday, September 15, 2008 7:12 AM
Para: 'Mike Louis'; 'root net'; Velasquez Venegas Jaime Omar
CC: cisco-nsp at puck.nether.net
Asunto: Re: [c-nsp] NTP not synchronizing

I have had similar problems in the past. I have found if your clock /
date are not set properly the router will refuse to accept the NTP
update as the offset is too large.

Also as suggested try multiple NTP servers. The fact that you are unable
to see the configured NTP servers' ref clock / stratum most likely
indicates some kind of comms issue. 

Cheers,

Aaron.



-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Mike Louis
Sent: Monday, September 15, 2008 7:40 PM
To: root net; Velasquez Venegas Jaime Omar
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] NTP not synchronizing

What source interface is the cisco client router using for NTP requests?
If its not configured it will use the outbound interface used to reach
the server. I saw an issue the other day where the external interface on
the WAN was not reachable by the NTP server at the home office and thus
they could not sync time. They changed the source interface to "ntp
source-interface Fax/x" (for their lan which was reachable) and were
able to get sync'd.

HTH

Mike

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of root net
Sent: Monday, September 15, 2008 12:17 AM
To: Velasquez Venegas Jaime Omar
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] NTP not synchronizing

What NTP server are you using?  Are you trying to use the Cisco router
as the NTP server for your clients/hosts on your network or what?  My
bet is the NTP server is overwhelmed you are trying to connect to.  I
had this issue before and changed NTP servers worked like a charm.
Check the NIST listing for an updated listing of NTP servers that are
free or with little users.

rootnet

On Sat, Sep 13, 2008 at 1:30 PM, Velasquez Venegas Jaime Omar <
Jaime at ulima.edu.pe> wrote:

> Hi there.
>
> I'm having a problem trying to synchronize a Cisco Router across a wan

> link with a NTP Server (No-Cisco router).So far i've ruled out packet 
> filering or firewall blocking as a cause of this.Some other equipments

> at the local side of this router actually synchronize with the ntp 
> server at our LAN.What strikes me is the fact that router does reach 
> ntp server via other protocols other than ntp tough.
>
>
> This is what i get from the out-of-sync router:
> #Show ntp assoc
>     address         ref clock     st  when  poll reach  delay  offset
> disp
> ~<<NTPServer>>    0.0.0.0          16     -    64    0     0.0    0.00
> 16000.
> * master (synced), # master (unsynced), + selected, - candidate, ~ 
> configured
>
> I've set debugging for the ntp packets and for all the traffic getting

> out of the serial interface which got "NTP: xmit packet to NTP.Server"
> events.However there 's absolutely no attempt whatsoever of packet 
> being transmitted to NTP Server at the serial interface.
> I've also configured this router as a ntp master and tried to get the 
> hosts on its local ethernet to synchronize with it to no avail.
>
> Any insight?
>
> Thanks
>
>
>
>
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net 
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


Note: This message and any attachments is intended solely for the use of
the individual or entity to which it is addressed and may contain
information that is non-public, proprietary, legally privileged,
confidential, and/or exempt from disclosure.  If you are not the
intended recipient, you are hereby notified that any use, dissemination,
distribution, or copying of this communication is strictly prohibited.
If you have received this communication in error, please notify the
original sender immediately by telephone or return email and destroy or
delete this message along with any attachments immediately.

_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.169 / Virus Database: 270.6.21/1670 - Release Date:
9/14/2008
7:16 AM

_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

More information about the cisco-nsp mailing list