3Com S7906E Configuration Manual page 2554

Figure 1-9 Network diagram for NTP broadcast mode configuration
Vlan-int3 Vlan-int3
1.0.1.11/24 1.0.1.10/24
Switch A
Configuration procedure
1) Configuration on Switch C:
# Specify the local clock as the reference source, with the stratum level of 2.
<SwitchC> system-view
[SwitchC] ntp-service refclock-master 2
# Configure Switch C to work in the broadcast server mode and send broadcast messages through
VLAN-interface 2.
[SwitchC] interface vlan-interface 2
[SwitchC-Vlan-interface2] ntp-service broadcast-server
2) Configuration on Switch D:
# Configure Switch D to work in the broadcast client mode and receive broadcast messages on
VLAN-interface 2.
<SwitchD> system-view
[SwitchD] interface vlan-interface 2
[SwitchD-Vlan-interface2] ntp-service broadcast-client
3) Configuration on Switch A:
# Configure Switch A to work in the broadcast client mode and receive broadcast messages on
VLAN-interface 3.
<SwitchA> system-view
[SwitchA] interface vlan-interface 3
[SwitchA-Vlan-interface3] ntp-service broadcast-client
Because Switch A and Switch C are on different subnets, Switch A cannot receive the broadcast
messages from Switch C. Switch D gets synchronized upon receiving a broadcast message from
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
Vlan-int2
3.0.1.31/24
Vlan-int2
3.0.1.30/24
Switch B
Vlan-int2
3.0.1.32/24
1-20
Switch C
Switch D