3Com Switch 8800 Family Configuration Guide

NTP Configuration 757
By default, no broadcast service is configured and the version number number
defaults to 3.
This command can only be configured on the interface where the NTP broadcast
packets will be transmitted.
Configuring NTP Broadcast Client Mode
Designate an interface on the local Switch to receive NTP broadcast messages and
operate in broadcast client mode. The local Switch listens to the broadcast from
the server. When it receives the first broadcast 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 broadcast client mode and continues listening
to the broadcast and synchronizes the local clock according to the broadcast
message that arrived .
Perform the following configuration in VLAN interface view.
This command can only be configured on the interface where the NTP broadcast
packets will be received.
Configuring NTP Multicast Server Mode
Designate an interface on the local Switch to transmit NTP multicast packets. In
this case, the local equipment operates in Multicast mode and serves as a
Multicast server to multicast messages to its clients regularly.
Perform the following configuration in VLAN interface view.
NTP version number number ranges from 1 to 3 and defaults to 3; the
authentication key ID keyid ranges from 1 to 4294967295; ttl-number of the
multicast packets ranges from 1 to 255; And the multicast IP address defaults to
224.0.1.1. Actually, for the Switch 8800 Family series, you can set 224.0.1.1 as the
multicast IP address only.
This command can only be configured on the interface where the NTP multicast
packet will be transmitted.
Tab le 702 Configure NTP broadcast client mode
Operation Command
Configure NTP broadcast client mode ntp-service broadcast-client
Disable NTP broadcast client mode undo ntp-service broadcast-client
Tab le 703 Configure NTP Multicast server mode
Operation Command
Configure NTP Multicast
server mode
ntp-service multicast-server [ ip-address ] [
authentication-keyid keyid | ttl ttl-number | version
number ]*
Cancel NTP Multicast server
mode
undo ntp-service multicast-server [ ip-address ]