3Com Switch 4800G 24-Port Configuration Manual page 954

954 C 77: NTP C
HAPTER ONFIGURATION
Configuring NTP
Server/Client Mode
n
Configuring the NTP
Symmetric Mode
n
For switches working in the server/client mode, you only need to make
configurations on the clients, and not on the servers.
Follow these steps to configure an NTP client:
To do... Use the command...
Enter system view system-view
Specify an NTP server ntp-service unicast-server { ip-address |
for the switch server-name } [ authentication-keyid keyid |
priority | source-interface interface-type
interface-number | version number ] *
In the ntp-service unicast-server command, ip-address must be a host
■
address, rather than a broadcast address, a multicast address or the IP address
of the local clock.
When the interface sending the NTP packet is specified by the
■
source-interface argument, the source IP address of the NTP packet will be
configured as the primary IP address of the specified interface.
A switch can act as a server to synchronize the clock of other switches 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.
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...
Enter system view system-view
Specify a ntp-service unicast-peer { ip-address |
symmetric-passive peer-name } [ authentication-keyid keyid |
peer for the switch priority | source-interface interface-type
interface-number | version number ] *
In the symmetric mode, you should use any NTP configuration command in
■
"Configuring the Operation Modes of NTP" on page 953 to enable NTP;
otherwise, a symmetric-passive peer will not process NTP packets from a
symmetric-active peer.
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.
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.
Remarks
-
Required
No NTP server is
specified by
default.
Remarks
-
Required
No symmetric-passive
peer is specified by
default.