Understanding the “NTP access-group” command in IOS.
NTP has always been one of those things I have found tricky to really lab up. Its fairly easy to setup, but verifying whether everything is working as you expect, can be hard because it takes a while to synchronize (and even unsynchronize).
NTP and modes of operation.
NTP is one of those things that really keeps messing with my head. To break it down, what does it do for us? Simple. It provides the correct time of the day. How does it accomplish this? Now this is where it gets interesting.