3Com S7906E Configuration Manual page 2556

# Configure Switch C to work in the multicast server mode and send multicast messages through
VLAN-interface 2.
[SwitchC] interface vlan-interface 2
[SwitchC-Vlan-interface2] ntp-service multicast-server
2) Configuration on Switch D:
# Configure Switch D to work in the multicast client mode and receive multicast messages on
VLAN-interface 2.
<SwitchD> system-view
[SwitchD] interface vlan-interface 2
[SwitchD-Vlan-interface2] ntp-service multicast-client
Because Switch D and Switch C are on the same subnet, Switch D can receive the multicast messages
from Switch C without being enabled with the multicast functions and can be synchronized to Switch C.
# View the NTP status of Switch D after clock synchronization.
[SwitchD-Vlan-interface2] display ntp-service status
Clock status: synchronized
Clock stratum: 3
Reference clock ID: 3.0.1.31
Nominal frequency: 100.0000 Hz
Actual frequency: 100.0000 Hz
Clock precision: 2^18
Clock offset: 0.0000 ms
Root delay: 31.00 ms
Root dispersion: 8.31 ms
Peer dispersion: 34.30 ms
Reference time: 16:01:51.713 UTC Sep 19 2005 (C6D95F6F.B6872B02)
As shown above, Switch D has been synchronized to Switch C, and the clock stratum level of Switch D
is 3, while that of Switch C is 2.
# View the NTP session information of Switch D, which shows that an association has been set up
between Switch D and Switch C.
[SwitchD-Vlan-interface2] display ntp-service sessions
source reference
**************************************************************************
[1234] 3.0.1.31 127.127.1.0
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations :
3) Configuration on Switch B:
Because Switch A and Switch C are on different subnets, you must enable the multicast functions on
Switch B before Switch A can receive multicast messages from Switch C.
# Enable IP multicast routing and IGMP.
<SwitchB> system-view
[SwitchB] multicast routing-enable
[SwitchB] interface vlan-interface 2
[SwitchB-Vlan-interface2] pim dm
[SwitchB-Vlan-interface2] quit
[SwitchB] vlan 3
stra reach
2 254
1
1-22
poll now offset delay
64 62 -16.0
disper
31.0 16.6