Setup NTP on Cisco Routers

How to setup NTP on Cisco Routers and check it is working.

In this How To, I will take you through the basic steps required to setup NTP on a Cisco Router. I will also show you the commands to use to make sure that it NTP is working and explain quickly what each step is doing.

First up, telnet to your router
>telnet <routerIP/hostname>

Enter Password

Check what the current time is set to
>show clock

Enter Enable mode

Enter Enable Password

Enter configure from terminal mode
#configure terminal

Enter the server[s] you want to use for NTP
#(conf)ntp server <ip address/hostname>
(repeat this step for all NTP servers you want)

Enter the interface you want to use to access the NTP server[s]
#(conf)ntp source <Interface>

Exit configure from terminal mode

If the clock was out by more than a few hours when you did show clock, you will need to set the clock on the router to the current time.
#clock set clock set hh:mm:ss <month> <1-31> <yyyy>

Now that the clock is set, give it a few min to connect to the NTP server and sync then you can check that NTP is working properly by using the following command
#show ntp associations

Once you are happy that it is all working and that the clock is in sync, make sure that you save the config
#copy running-config startup-config

Now you are all done and can exit your router