Hello,
I have a problem with the time synchronization via NTP between a Catalyst 2960 and Catalyst 6509. When I configure the 6509 switch as a NTP reference on the 2960, it does not synchronize with the 6509's NTP server. There is no reachability or ACL-related issue between both switches.
As soon as I configure a second Catalyst 6509 (which is completely identical to the other 6509 and in the same subnet) as a NTP server for the 2960, the time sync with the second 6509 happens immediality.
The first 6509 switch works as a NTP reference for at least 50 other switches and routers in the network - so why not for this one more switch? I checked some "debug ntp packet" and "debug ntp events" outputs and can clearly watch the NTP requests going out of the 2960, but on the 6509 just nothing happens - no debug outputs for this specific 2960, while requests from other devices come in all the time.
Maybe you have already experienced this strange behaviour in the past or got some deeper knowledge in the Cisco NTP server implementation. I could think of some sort of "maximum client limit" in the IOS NTP server, but could not find any mechanism like this in the standard NTP specification. Eventually, you can approve that this is a IOS-specific issue.
Any help or hint is highly appreciated. Thank you!
Regards
Dennis
