3Com 4500G Family Configuration Manual page 1163

Figure 1-10 Network diagram for NTP multicast mode configuration
Configuration procedure
1) Configure IP addresses for interfaces (omitted)
2) Configuration on Switch C:
# Configure Switch C to work in the multicast server mode and send multicast messages through
VLAN-interface 2.
<SwitchC> system-view
[SwitchC] interface vlan-interface 2
[SwitchC-Vlan-interface2] ntp-service multicast-server
3) 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: 64.0000 Hz
Actual frequency: 64.0000 Hz
Clock precision: 2^7
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)
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