H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 506)

54-21
As shown above, AC D has been synchronized to AC C, and the clock stratum level of AC D is 3, while
that of AC C is 2.
# View the NTP session information of AC D, which shows that an association has been set up between
AC D and AC C.
[AC D-Vlan-interface2] display ntp-service sessions
source reference stra reach poll now offset delay disper
**************************************************************************
[1234] 3.0.1.31 127.127.1.0 2 254 64 62 -16.0 31.0 16.6
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations : 1
3) Configuration on AC B:
Because AC A and AC C are on different subnets, you must enable IGMP on AC B before AC A can
receive multicast messages from AC C.
# Enable IP multicast routing and IGMP.
system-view
[AC B] multicast routing-enable
[AC B] interface vlan-interface 2
[AC B-Vlan-interface2] pim dm
[AC B-Vlan-interface2] quit
[AC B] vlan 3
[AC B-vlan3] port GigabitEthernet 0/0/1
[AC B-vlan3] quit
[AC B] interface vlan-interface 3
[AC B-Vlan-interface3] igmp enable
[AC B-Vlan-interface3] quit
[AC B] interface GigabitEthernet 0/0/1
[AC B-GigabitEthernet0/0/1] igmp-snooping static-group 224.0.1.1 vlan 3
4) Configuration on AC A:
# Enable IP multicast routing and IGMP.
system-view
[AC A] interface vlan-interface 3
# Configure AC A to work in the multicast client mode and receive multicast messages on
VLAN-interface 3.
[AC A-Vlan-interface3] ntp-service multicast-client
# View the NTP status of AC A after clock synchronization.
[AC A-Vlan-interface3] 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: 40.00 ms
Root dispersion: 10.83 ms
Peer dispersion: 34.30 ms
Reference time: 16:02:49.713 UTC Apr 20 2007 (C6D95F6F.B6872B02)