Configuring Ntp Multicast Mode - 3Com 4510G Configuration Manual

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: 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)
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-Vlan-interface2] display ntp-service sessions
source
**************************************************************************
[1234] 3.0.1.31 127.127.1.0
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations : 1

Configuring NTP Multicast Mode

Network requirements
The local clock of Switch C is to be used as the master clock, with a stratum level of 2.
Switch C works in the multicast server mode and sends out multicast messages from
VLAN-interface 2.
Switch A and Switch D work in the multicast client mode and receive multicast messages through
VLAN-interface 3 and VLAN-interface 2 respectively.
In this example, Switch B is a L3 switch and it must support the IGMP function.
reference stra reach poll now
2 254
offset
64 62 -16.0 32.0
24-19
delay disper
16.6