NTP PEER question!

Hi Experts,
I am confused of when we need to use the peer keyword in NTP:checked:
https://www.cisco.com/en/US/docs/ios/12_2/configfun/command/reference/frf012.
html#wp1122955
But still if I only want to synchronize R1 with server R2, I only need:R1: ntp
server R1(IP add of R1)R2: ntp master
so when do I need to use ntp peer .... ?

Moreover I have my first Mock lab v4 R&S this Sat, any advice.

Thanks,
Received on Tue May 25 2010 - 17:33:07 ART