December 2006
Intermediate to advanced
1188 pages
72h 8m
English
Content preview from Cisco IOS Cookbook, 2nd EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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NTP Logging
Problem
You want to log significant NTP events.
Solution
Use the ntp logging command to enable the logging of NTP events:
Router2#configure terminalEnter configuration commands, one per line. End with CNTL/Z. Router2(config)#ntp loggingRouter2(config)#endRouter2#
Discussion
Starting in IOS Version 12.3(7)T, Cisco added the NTP logging feature. By implementing this feature, the router will log significant NTP events such as peer loss, peer reachability, and clock synchronization events.
To view the NTP logging events on the router, use the following command:
Router2#show logging | include NTP
000019: Jan 29 10:57:52.633 EST: %NTP-5-PEERSYNC: NTP synced to peer 172.25.1.5
000020: Jan 29 10:57:52.637 EST: %NTP-6-PEERREACH: Peer 172.25.1.5 is reachable
000023: Jan 29 10:57:53.635 EST: %NTP-6-PEERREACH: Peer 172.25.1.3 is reachable
000024: Jan 29 11:01:20.653 EST: %NTP-4-PEERUNREACH: Peer 172.25.1.5 is unreachable
000026: Jan 29 11:15:11.985 EST: %NTP-4-UNSYNC: NTP sync is lost
Router2#In this example, we can see that the router initially
synchronized its time to server 172.25.1.5 before the server became
unreachable, causing the router to lose synchronization. This kind of
forensic information can assist you in investigating NTP
issues.
See Also
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.