H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 494)

54-9
Configuring the NTP Symmetric Mode
For switches working in the symmetric mode, you need to specify a symmetric-passive on a
symmetric-active peer.
Following these steps to configure a symmetric-active switch:
To do… Use the command… Remarks
Enter system view system-view —
Specify a
symmetric-passive peer
for the switch
ntp-service unicast-peer { ip-address |
peer-name } [ authentication-keyid keyid | priority
| source-interface interface-type interface-number
| version number ] *
Required
No symmetric-passive peer
is specified by default.
z
In the symmetric mode, you should use any NTP configuration command in Configuring the
Operation Modes of NTP to enable NTP; otherwise, a symmetric-passive peer will not process
NTP packets from a symmetric-active peer.
z
In the ntp-service unicast-peer command, ip-address must be a host address, rather than a
broadcast address, a multicast address or the IP address of the local clock.
z
When the interface used to send NTP messages is specified by the source-interface argument,
the source IP address of the NTP message will be configured as the primary IP address of the
specified interface.
z
Typically, at least one of the symmetric-active and symmetric-passive peers has been
synchronized; otherwise the clock synchronization will not proceed.
z
You can configure multiple symmetric-passive peers by repeating the ntp-service unicast-peer
command.
Configuring NTP Broadcast Mode
The broadcast server periodically sends NTP broadcast messages to the broadcast address
255.255.255.255. After receiving the messages, the switch working in NTP broadcast mode sends a
reply and synchronizes its local clock.
For switches working in the broadcast mode, you need to configure both the server and clients.
Because an interface need to be specified on the broadcast server for sending NTP broadcast
messages and an interface also needs to be specified on each broadcast client for receiving broadcast
messages, the NTP broadcast mode can be configured only in the specific interface view.