When config NTP to use an Internet time source it is advisable to use
DNS as its IP address might be cx from time to time. (no pun intended)
The prob I have if it is entered as such eg
NTP server ntp.tock.tick.com
It is resolved to an IP address and stored as such in the config eg
ntp server 123.123.123.123
What happens if the provider alters the ip address??
Ken Williams
The cisco box will continue to send its packets out into the ether, and if
there are no valid servers left, the clock will free-run at the last
frequency calculated by NTP (as will any box trying to sync to this box).
This issue isn't unique to NTP (the same holds true for any other server
you can configure on the cisco box). Don't know if there's been any
progress in fixing this since I left. It's not terribly hard to fix, but
it isn't trivial either.