NTP Server - Not syncing

oli356

Hi all,

I am trying to setup a Cisco 7200 as an NTP server, well it is getting its time from our AD server which is pulling it from the internet.

The config on the router is

ntp authentication-key 1 md5 075E711D6B5C3D5134472F58537E7B7109666C7747574F54580608 7
ntp authenticate
ntp trusted-key 1
ntp clock-period 17179568
ntp source GigabitEthernet0/1
ntp master 5
ntp update-calendar
ntp server 9.9.6.231 prefer

But when I do a show ntp associate

NTP-A#sh ntp ass

address ref clock st when poll reach delay offset disp
~9.9.6.231 9.9.6.232 2 250 1024 377 1.4 275974 12.2
*~127.127.7.1 127.127.7.1 4 59 64 377 0.0 0.00 0.0
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

So the st is lower than the 127 address, so I thought it would become the master and sync... but it isn't.

Any suggestions? Thanks!

azaghul

NTP on a router can take quite some time to sync from an external device, in my case my 877 can take at least 10mins from power up. I point mine to the ntp.org server pools.

From my understanding Windows uses SNTP (Simple NTP) instead, which is another reason you might be having problems. Try sntp server 9.9.6.231 instead.

oli356

Device has been on a few days so it can't be that.

I am unsure why I have been told to sync from the AD instead of just syncing from the same source as the AD is. Well actually this is AD-1, which is pointing at AD-2 (backup) for the time which is then getting time from the internet.. Confuses me. I thought this is how it was configured anyway, though 9.9.6.232 (ad-2) says local, and not an address on the internet.


sntp isn't a command, at least on this router.

Thanks

DCD

Make sure the server is an authoritative server for NTP also make sure it's allowing access to the NTP port (UDP 123) and that the service is started. After that you may have to wait 20 minutes for it to sync.

oli356

Not sure what the issue was, no firewalls or anything.

In the end I had the 2 7200s syncing to our 3650 switch provided by the ISP. Then I had the Windows AD servers just pull the time from there also, made more sense!