3Com 4500G Family Configuration Manual page 1161

Configuration procedure
1) Configure IP addresses for interfaces (omitted)
2) Configuration on Switch C:
# 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
3) Configuration on Switch A:
# Configure Switch A to work in the broadcast client mode and receive broadcast messages on
VLAN-interface 2.
<SwitchA> system-view
[SwitchA] interface vlan-interface 2
[SwitchA-Vlan-interface2] ntp-service broadcast-client
4) Configuration on Switch B:
# Configure Switch B to work in the broadcast client mode and receive broadcast messages on
VLAN-interface 2.
<SwitchB> system-view
[SwitchB] interface vlan-interface 2
[SwitchB-Vlan-interface2] ntp-service broadcast-client
Switch A gets synchronized upon receiving a broadcast message from Switch C.
# View the NTP status of Switch A after clock synchronization.
[SwitchA-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 A has been synchronized to Switch C, and the clock stratum level of Switch A
is 3, while that of Switch C is 2.
# View the NTP session information of Switch A, which shows that an association has been set up
between Switch A and Switch C.
[SwitchA-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 :
stra reach poll
2 254
1
1-20
now offset delay
64 62 -16.0 32.0
disper
16.6