3Com 8800 Configuration Manual page 726

3Com Switch 8800 Configuration Guide
IV. Configuring NTP Broadcast Client Mode
Designate an interface on the local Ethernet Switch to receive NTP broadcast
messages and operate in broadcast client mode. The local Ethernet 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 Ethernet Switch enters broadcast client mode and
continues listening to the broadcast and synchronizes the local clock according to the
arrived broadcast message.
Perform the following configuration in VLAN interface view.
Table 49-4 Configure NTP broadcast client mode
Configure NTP broadcast client mode
Disable NTP broadcast client mode
This command can only be configured on the interface where the NTP broadcast
packets will be received.
V. Configuring NTP Multicast Server Mode
Designate an interface on the local Ethernet 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.
Table 49-5 Configure NTP multicast server mode
Configure NTP multicast server
mode
Cancel NTP multicast server mode
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, 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.
Operation
Operation
49-5
Chapter 49 NTP Configuration
Command
ntp-service broadcast-client
undo ntp-service broadcast-client
Command
ntp-service multicast-server [ ip-address ]
[ authentication-keyid keyid | ttl ttl-number
| version number ]*
undo ntp-service
[ ip-address ]
multicast-server