Cisco IOS Cookbook, 2nd Edition

Checking the NTP Status

Problem

You want to verify the status of NTP on your router to make sure it’s running properly.

Solution

Use the NTP and clock show commands to verify the status of NTP on your router. The best place to start is the show clock detail command, which provides information on the current time, time source, and time zone configuration:

Router>show clock detail 
15:54:33.079 EST Sun Jan 29 2006
Time source is NTP
Summer time starts 02:00:00 EST Sun Apr 2 2006
Summer time ends 02:00:00 EDT Sun Oct 29 2006
Router>

To display the current NTP status of the local router, the command is:

Router>show ntp status

The command to display the current NTP associations is:

Router>show ntp associations 

And you can display detailed information about the current NTP associations with the following command:

Router>show ntp associations detail 

Discussion

You can view the current clock status by using the show clock detail command:

Router>show clock detail 
.15:54:33.079 EST Sun Jan 29 2006
Time source is NTP
Summer time starts 02:00:00 EST Sun Apr 2 2006
Summer time ends 02:00:00 EDT Sun Oct 29 2006
Router>

In this example, the router’s current date and time are correctly set, but notice the period or decimal appended to time (some routers display an asterisk instead of a period). This indicates that NTP is unsynchronized and will appear on show commands and log messages. Recognizing the significance of the period highlights problems with NTP even when you are not specifically looking for timing ...