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Can I use cisco 2610 as a NTP master

aliaghag
Level 1
Level 1

I have cisco two 7206 and over 100 cisco 2600 routers. I have set up the 7206 and the 2610 routers as a NTP servers. The 2610 will get there NTP time from the 7206 while the 7206 will get NTP time from External. My Windows NT servers can get NTP time from the 7206 but can not get NTP time from the 2600 routers.

How can I configure the cisco 2600 to be a NTP time server to my LAN

This is how I configured the 2610 routers. these same config worked on 7206

but not working on the 2610.

internet Ethernet0

ntp broadcast

clock timezone EST -5

clock summer-time CDT recurring

NTP master 4

ntp server 160.1.2.1

ntp server 160.1.1.1

2 Replies 2

thomas.chen
Level 6
Level 6

According to some documentation you want to be careful assigning every router the NTP MASTER command. Look over this link that discusses setting up NTP PEERs. http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/fun_c/fcprt3/fcd303.htm#13162

ggersch
Level 1
Level 1

First, you don't want to be using the 'ntp master' command. This is overriding the 'ntp server' statements below, and basically cutting your ntp tree off. I'm guessing that the two ntp server statements are pointing at your 7206 routers?

That should work fine. Are the 7206s set to peer to each other? What external servers are they using?

Use the 'sho ntp assoc' and 'sho ntp status' commands to verify that the 2610s are properly synced with the 7206s. Until these commands show the 2610s are synced, the nt servers won't be able to get time from them.

Also, you probably don't want to use 'ntp broadcast'. All this does is add garbage broadcasts to your network. Unless you know for sure that you have passive ntp clients listening for broadcasts, which is rare, take it out.

What time client are you using on your ntp servers? If you are using the w32time service, what does the 'net time /querysntp' command show? Is it specifying the correct name/ip of the local 2610?

To verify that the 2610s are providing ntp services, you need the ntp client tools. Most Unix machines have them. You can get an NT port of the latest NTP program at http://www.five-ten-sg.com . Get the NTP 4.1.71 file. The tools you want are 'ntptrace' and 'ntpq'. 'ntptrace' verifies the chain of ntp servers to the stratum 1 root. 'ntpq' is an interactive program that shows the same info as the 'sho ntp' cisco commands and more. Use these on your nt server to verify they can pull time from the 2610s.

Everything you really want to know about ntp, and more, can be found at:

http://www.eecis.udel.edu/~ntp/

Greg