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New Member

NTP is configured, but not syncing.

Good Day,

We have a 6500 switch that we are trying to sync with a 7206 router. The switch shows that NTP is configured, but not synced.

I ran a debug ntp packet on both the switch and the router.

The switch is transmitting NTP requests to the router.

The router is receiving those request and transmitting replies back to the switch.

The switch doesn't seem to get the replies.

any ideas?

Cisco Employee

Re: NTP is configured, but not syncing.

The router will send an NTP reply back to the switch from UDP port 123 to UDP port 123. If there are ACLs or firewalls blocking that traffic, they would need to be modified.

New Member

Re: NTP is configured, but not syncing.

Hi and thank you for your reply.

There is actually a device in between the router and the switch in question.

It is a Juniper Caching engine. From all of my reading, it should not cause a problem; but what you have said really makes sence. I will have to follow that up.


New Member

Re: NTP is configured, but not syncing.

Do you have the same timezones on both devices, and have you set the time of the switch near the time of the router, because i am not sure on cisco, but on unix it doesnot synchronise if the time difference is mor the some minutes.