3Com Switch 7750 Series
Command Reference Guide – NTP Chapter 1 NTP Configuration Commands
1-10
1.1.12 ntp-service multicast-client Syntax
ntp-service multicast-client [ ip-address ]
undo ntp-service multicast-client [ ip-address ]
View
VLAN interface view
Parameter
ip-address: Specifies a multicast IP address of Class D.
Description
Use the ntp-service multicast-client command to configure the NTP multicast client
mode.
Use the undo ntp-service multicast-client command to disable the NTP multicast
client mode.
By default, the multicast client service is disabled. ip-address defaults to 224.0.1.1.
Designate an interface on the local device to receive NTP multicast packets. The local
device operates in the multicast client mode. The local device listens to the multicast
packets from the server. When it receives the first multicast packet, it starts a brief
client/server mode to exchange messages with a remote server for estimating the
network delay. Thereafter, the local device enters the multicast client mode and
continues listening to the multicast packets and synchronizes the local clock based on
the arrived multicast message.
Example
# Configure to receive NTP multicast packets to the multicast group address of
224.0.1.1 through Vlan-interface1.
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] interface vlan-interface 1
[3Com-Vlan-Interface1] ntp-service multicast-client 224.0.1.1
1.1.13 ntp-service multicast-server Syntax
ntp-service multicast-server [ ip-address ] [ authentication-keyid keyid ] [ ttl
ttl-number ] [ version number ]*
undo ntp-service multicast-server [ ip-address ]