H3C H3C S5100-SI, Operation Manual, Page: 561 / 830

1-4
NTP Implementation Modes
According to the network structure and the position of the local Ethernet switch in the network, the local
Ethernet switch can work in multiple NTP modes to synchronize the clock.
Server/client mode
Figure 1-2 Server/client mode
Symmetric peer mode
Figure 1-3 Symmetric peer mode
Passive peer
Clock synchronization
request packet
Synchronize
Network
Active peer
Works in passive peer
mode automatically
In peer mode, both sides
can be synchronized to
each other
Response packet
In the symmetric peer mode, the local S5100-SI/EI Ethernet switch serves as the symmetric-active peer
and sends clock synchronization request first, while the remote server serves as the symmetric-passive
peer automatically.
If both of the peers have reference clocks, the one with a smaller stratum number is adopted.