3Com Switch 4800G 24-Port Configuration Manual page 966

966 C 77: NTP C
HAPTER ONFIGURATION
# View the NTP status of Switch D after clock synchronization.
[SwitchD] 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: 2^7
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 Apr 20 2007 (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] 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 IGMP
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
[SwitchB-vlan3] port GigabitEthernet 1/0/1
[SwitchB-vlan3] quit
[SwitchB] interface vlan-interface 3
[SwitchB-Vlan-interface3] igmp enable
[SwitchB-Vlan-interface3] quit
[SwitchB] interface GigabitEthernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] igmp-snooping static-group 224.0.1.1 vlan 3
4 Configuration on Switch A:
# Enable IP multicast routing and IGMP.
<SwitchA> system-view
[SwitchA] interface vlan-interface 3
# Configure Switch A to work in the multicast client mode and receive multicast
messages on VLAN-interface 3.
[SwitchA-Vlan-interface3] ntp-service multicast-client
stra reach poll
2 254 64
1
now offset delay
62 -16.0 31.0 16.6
disper