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New Member

NTP Falseticker


I've got nearly 300 devices to synch with my core router (7206)as master , Core router itself synchs with a Major tier 1 NTP server.

Last night I upgraded to 12.4.22T from 12.4.15,

From last night after upgrade I get this falseticker error and NTP virtually dies.

It initially works for a couple of minutes then dies , right now I'm pushing out the clock which is manually set.

The internal clock is fine and correctly set I suppose there is something wrong between the internal clock and what it gets from the server.

Wondered if anyone has face this before.


New Member

NTP Falseticker

I am having the same issue. My core NTP server is a 4507R+E (Sup 7) and I have several routers synced to to it. I upgrades a 2821 to 12.4.22T yesterday and now the router shows this server as a falseticker. Does anyone know what the issue might be?


Cisco Employee

NTP Falseticker

I also had this issue, and when looking around.

Apparently it has to do with the fact that after 12.4(15)T IOS NTPv4 is supported, prior to this it was NTPv3, which has far stricter parameters around what it deems to be a viable time source. So the NTP clocks I had configured under 12.4(15)T all went into a state of falseticker. I randomly set new publicly available NTP servers until I fouind one that sync'd up.

I hope this helps

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