3Com 4200G 48-Port - Configuring NTP Multicast Mode

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# Set Device A as a broadcast client.
[DeviceA] interface Vlan-interface 2
[DeviceA-Vlan-interface2] ntp-service broadcast-client
After the above configurations, Device A and Device D will listen to broadcast messages through their
own VLAN-interface 2, and Device C will send broadcast messages through VLAN-interface 2.
Because Device A and Device C do not share the same network segment, Device A cannot receive
broadcast messages from Device C, while Device D is synchronized to Device C after receiving
broadcast messages from Device C.
View the NTP status of Device D after the clock synchronization.
[DeviceD] display ntp-service status
Clock status: synchronized
Clock stratum: 3
Reference clock ID: 3.0.1.31
Nominal frequency: 60.0002 Hz
Actual frequency: 60.0002 Hz
Clock precision: 2^18
Clock offset: 198.7425 ms
Root delay: 27.47 ms
Root dispersion: 208.39 ms
Peer dispersion: 9.63 ms
Reference time: 17:03:32.022 UTC Apr 2 2007 (BF422AE4.05AEA86C)
The output information indicates that Device D is synchronized to Device C, with the clock stratum level
of 3, one level lower than that of Device C.
# View the information about the NTP sessions of Device D and you can see that a connection is
established between Device D and Device C.
[DeviceD] display ntp-service sessions
source reference stra reach poll now offset delay disper
**************************************************************************
[1234]3.0.1.31 127.127.1.0 2 1 64 377 26.1 199.53 9.7
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured Total
associations : 1
Configuring NTP Multicast Mode
Network requirements
z The local clock of Device C is set as the NTP master clock, with a clock stratum level of 2.
Configure Device C to work in the NTP multicast server mode and advertise multicast NTP
messages through VLAN-interface 2.
z Device A and Device D are two S4200G Ethernet switches. Configure Device A and Device D to
work in the NTP multicast client mode and listen to multicast messages through their own
VLAN-interface 2.