3Com Switch 8800 Family Configuration Guide

758 CHAPTER 66: NTP CONFIGURATION
Configuring NTP Multicast Client Mode
Designate an interface on the local Switch to receive NTP multicast messages and
operate in multicast client mode. The local Switch listens to the multicast from the
server. When it receives the first multicast packets, it starts a brief client/server
mode to switch messages with a remote server for estimating the network delay.
Thereafter, the local Switch enters multicast client mode and continues listening to
the multicast and synchronizes the local clock by the multicast message that
arrived.
Perform the following configuration in VLAN interface view.
Multicast IP address ip-address defaults to 224.0.1.1; this command can only be
configured on the interface where the NTP multicast packets will be received.
Actually, for the Switch 8800 Family series, you can set 224.0.1.1 as the multicast
IP address only.
Configuring NTP ID
Authentication
Enable NTP authentication, set MD5 authentication key, and specify the reliable
key. A Client will synchronize itself by a server only if the serve can provide a
reliable key.
Perform the following configuration in system view.
Setting NTP
Authentication Key
This configuration task is to set NTP authentication key.
Perform the following configuration in system view.
Key number number ranges from 1 to 4294967295; the key value contains 1 to
16 ASCII characters.
Setting Specified Key as
Reliable
This configuration task is to set the specified key as reliable.
Perform the following configuration in system view.
Tabl e 704 Configure NTP multicast client mode
Operation Command
Configure NTP multicast client mode ntp-service multicast-client [ ip-address ]
Cancel NTP multicast client mode undo ntp-service multicast-client
Tabl e 705 Configure NTP authentication
Operation Command
Enable NTP authentication ntp-service authentication enable
Disable NTP authentication undo ntp-service authentication enable
Tabl e 706 Configure NTP authentication key
Operation Command
Configure NTP
authentication key
ntp-service authentication-keyid number
authentication-mode md5 value
Remove NTP
authentication key
undo ntp-service authentication-keyid number