In this mode, there are two time consumers or time providers. Both of them can request the time from each other and respond to each other. They are at the same level and therefore, known as peers.
Figure 3-3 Peer-to-Peer Mode
If you want to use the servers in this mode, add the following line to the ntp.conf file of each server:
peer IP_address_of_the_other_server
See Section 4.3, Wide Area Configuration for more information.