3Com 4210 PWR Configuration Manual page 375

Configuring the NTP
Symmetric Peer Mode
n
Configuring NTP
Broadcast Mode
n
For switches working in the symmetric peer mode, you need to specify a
symmetric-passive peer on the symmetric-active peer.
Table 284 Configure a symmetric-active switch
Operation
Enter system view
Specify a symmetric-passive
peer for the switch
In the symmetric peer mode, you need to execute the related NTP
■
configuration commands (refer to "Configuring NTP Implementation Modes"
for details) to enable NTP on a symmetric-passive peer; otherwise, the
symmetric-passive peer will not process NTP messages from the
symmetric-active peer.
The remote device specified by remote-ip or peer-name serves as the peer of
■
the local Ethernet switch, and the local switch works in the symmetric-active
mode. In this case, the clock of the local switch and that of the remote device
can be synchronized to each other.
remote-ip must not be a broadcast address, a multicast address or the IP
■
address of the local clock.
After you specify an interface for sending NTP messages through the
■
source-interface keyword, the source IP address of the NTP message will be
configured as the IP address of the specified interface.
Typically, the clock of at least one of the symmetric-active and
■
symmetric-passive peers should be synchronized first; otherwise the clock
synchronization will not proceed.
You can configure multiple symmetric-passive peers for the local switch by
■
repeating the ntp-service unicast-peer command. The clock of the peer with
the smallest stratum will be chosen to synchronize with the local clock of the
switch.
For switches working in the broadcast mode, you need to configure both the
server and clients. The broadcast server periodically sends NTP broadcast messages
to the broadcast address 255.255.255.255. The switches working in the NTP
broadcast client mode will respond to the NTP messages, so as to start the clock
synchronization.
A 3Com Switch 4210 can operate as a broadcast server or a broadcast client.
Refer to Table 285 for configuring a switch to work in the NTP broadcast server
■
mode.
Refer to Table 286 for configuring a switch to work in the NTP broadcast client
■
mode.
A broadcast server can synchronize broadcast clients only after its clock has been
synchronized.
Configuring NTP Implementation Modes
Command
system-view
ntp-service unicast-peer {
remote-ip | peer-name } [
authentication-keyid key-id
| priority | source-interface
Vlan-interface vlan-id |
version number ]*
373
Description
-
Required
By default, a switch is not
configured to work in the
symmetric mode.