H3C Technologies H3C SecPath F1000-E - Manual (Page 116)

105
receipt of a message, rather than creating an association (static or dynamic). In symmetric mode,
static associations are created at the symmetric-active peer side, and dynamic associations are
created at the symmetric-passive peer side. In broadcast or multicast mode, static associations are
created at the server side, and dynamic associations are created at the client side.
Configuring the NTP client/server mode
Configuration guidelines
• If you specify the source interface for NTP messages by specifying the source interface
source-interface option, NTP uses the primary IP address of the specified interface as the source IP
address of the NTP messages.
• A router can act as a server to synchronize the clock of other routers only after its clock has been
synchronized. If the clock of a server has a stratum level higher than or equal to that of a client's
clock, the client will not synchronize its clock to the server's.
• You can configure multiple servers by repeating the ntp-service unicast-server command. The
clients will choose the optimal reference source.
Configuration procedure
To configure an NTP client:
Step Command Remarks
1. Enter system
view.
system-view N/A
2. Specify an NTP
server for the
device.
ntp-service unicast-server [ vpn-instance
vpn-instance-name ] { ip-address | server-name }
[ authentication-keyid keyid | priority |
source-interface interface-type interface-number
| version number ] *
By default, no NTP server is
specified.
In this command, the ip-address
argument must be a unicast
address, rather than a broadcast
address, a multicast address or the
IP address of the local clock.
Configuring the NTP symmetric peers mode
Configuration guidelines
• To enable NTP, use the ntp-service refclock-master command or any NTP configuration command
in " Configuring the NTP operation modes ." Otherwise, a symmetric-passive peer will not process
NTP messages from a symmetric-active peer.
• After you specify the source interface for NTP messages by specifying the source interface
source-interface option, the source IP address of the NTP messages is set as the primary IP address
of the specified interface.
• Either the symmetric-active peer or the symmetric-passive peer must be in synchronized state.
Otherwise, the clock synchronization does not proceed.
• You can configure multiple symmetric-passive peers by repeating the ntp-service unicast-peer
command.