H3C S7500 Series Operation Manual page 802

Operation Manual – NTP
H3C S7500 Series Ethernet Switches
II. Peer mode
In peer mode, both sides
can be synchronized to
each other
Figure 1-3 NTP implementation mode: peer mode
In peer mode, the active peer sends clock synchronization packets first, and its peer
works as a passive peer automatically.
If both of the peers have reference clocks, the one with smaller stratum is adopted.
III. Broadcast mode
Works in the server mode
automatically and sends
response packets
Figure 1-4 NTP implementation mode: broadcast mod
IV. Multicast mode
Works in the server mode
automatically and sends
response packets
Figure 1-5 NTP implementation mode: multicast mod
Active peer
Network
Clock synchronization
request packet
Response packet
Synchroni z e
Server
Network
Broadcast clock synchronizati on
packets periodically
Client/server mode
reques
Response packet
Broadcast clock synchronizati on
packets periodically
Server
Network
Multicast clock synchronizati on
packets periodically
Client/server mode
reques
Response packet
Multicast clock synchronizati on
packets periodically
Passive peer
W orks in passive peer
m ode automatically
Client
Initiates a c
request af
first broadca
Obtains th
client and s
the broadca
Receives br
synchronizes
e
Client
Initiates a c
request af
first multicas
Obtains the
client and s
the multicas
Receives mu
synchronizes
e
1-4
Chapter 1 NTP Configuration
lient/server mode
ter receiving the
st packet
e delay between the
erver and works in
st client mode
oadcast packets and
the local clock
lient/server mode
ter receiving the
t packet
delay between the
erver and works in
t client mode
lticast packets and
the local clock