Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

831 clock time is incorrect

I'm not sure if I'm in the correct forum but I have a Cisco 831 router which seems to have the incorrect time listed. When I type in the command "show clock" I receive an EST time of 7 hours ahead, a date in March and the year 2002. There are NTP commands listed in the config which are the same that are used in our entire network however for this router the time remains incorrect. In config mode I noticed some clock commands I could use but they seemed doubtful. Does anyone know the correct commands to use to correct the time? Also, the router is connected to the ethernet port of a dsl modem and is using vpn tunneling to get out to the net. Could the clock problem cause any loss of connection? Thanks.

Hall of Fame Super Silver

Re: 831 clock time is incorrect


This forum is probably as good as any for posting your question.

I very much doubt that the clock problem could cause any loss of connection (though loss of connection might cause the clock problem).

I very much expect that there is some problem with NTP on that router. If you would post the output of show ntp association, we should be able to confirm that.

Can you confirm whether you have IP connectivity from this router to the configured NTP server(s)?

The clock commands in config mode have to do with what offset from GMT you are in and whether to observe daylight savings time. I doubt that they are involved in your problem.

It might help us figure out the issue if you would post the parts of the configuration that deal with NTP.



New Member

Re: 831 clock time is incorrect


Thanks for replying. Currently this site is down but I've compared other sites that were down and have similar ntp commands in their config and even when they are down the clock/date/time are never off by as much that I saw on this router. Here is the last part of the config listing ntp commands and the show ntp association command results.............

ntp clock-period 17179531

ntp source Ethernet0

ntp server prefer


AF_VR_02652001_01#show ntp association

address ref clock st when poll reach delay offset disp

~ 16 - 64 0 0.0 0.00 16000.

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

.......Let me know if that was what you needed. Thanks.....Danny

Hall of Fame Super Silver

Re: 831 clock time is incorrect


Thanks for posting the additional information. The NTP configuration is pretty straightforward. The show ntp associations gives proof that the router is not talking to the NTP server. But if the site is down then it is understandable. I would want to see the output of this command when the site is up.

My theory is that there is something that is preventing this router from learning time from the server. Many of the lower end routers do not have a clock chip that remembers time over a power cycle or a reload. So when they start they assume time from some arbitrary point and that sounds like what your router is doing. For these routers it is advisable to run NTP and to let them learn time from a server in the network. Once they have learned correct time from a server they will keep pretty good time, even if they lose contact with the server. But until they can learn time from the server the time that they show will be greatly off.

So when the site is up, try the command again and let us know what it shows.



New Member

Re: 831 clock time is incorrect

Your lucky..

ROUTER-831-1(config)#ntp server


% Invalid input detected at '^' marker.

Version 12.3(2)XC2