Re: NTP Configuration

croftsd23 · ‎08-19-2020

I am looking at NTP configuration and have the following configuration:-

ip access-list standard NTP
permit x.x.x.x
deny any log

access-list 23 deny any log

ntp access-group peer NTP
ntp access-group serve-only 23
ntp server prefer x.x.x.x

The result I am seeing is that when I apply debug I can see downward devices getting blocked. However, the devices do appear to be getting a response from the server. There lies my confusion.

marce1000 · ‎08-19-2020

access-list 23 deny any log -> Doesn't that overall-deny match first ?

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

croftsd23 · ‎08-19-2020

Thanks for the reply. I see the configuration working as follows:-

The switch is able to peer with the NTP server but due to the deny access list, all downward devices attempting to get a time source should fail. I see blocks in the log. However, the devices are getting a time reply?