3Com Switch 7750 Configuration Guide Guide
Configuration Example 711
# Enter VLAN-interface 2 view.
[[Switch 7750-1] interface vlan-interface 2
# Configure Switch 7750-4 to be a multicast client.
[Switch 7750-1-Vlan-interface2] ntp-service multicast-client
3 Configure Switch 7750-2.
# Enter system view.
<Switch 7750-2> system-view
[Switch 7750-2]
# Enter VLAN-interface 2 view.
[[Switch 7750-2] interface Vlan-interface 2
# Configure Switch 7750-2 to be a multicast client.
[Switch 7750-2-Vlan-Interface2] ntp-service multicast-client
The above configuration configures Switch 7750-1 and Switch 7750-2 to listen to
multicast packets through their VLAN interface 2, and Switch 7750-3 to advertise
multicast packets through VLAN interface 2. Because Switch 7750-2 does not
reside in the same network segment with Switch 7750-3, Switch 7750-2 cannot
receive multicast packets sent by Switch 7750-3, while Switch 7750-1 is
synchronized to Switch 7750-3 after receiving multicast packets sent by Switch
7750-3.
View the status of Switch 7750-1 after the synchronization.
[Switch 7750-1] display ntp-service status
Service status: enabled
Clock status: synchronized
Clock stratum: 3
Reference clock ID: 3.0.1.31
Nominal frequency: 250.0000 Hz
Actual frequency: 249.9992 Hz
Clock precision: 2^19
Clock offset: 198.7425 ms
Root delay: 27.47 ms
Root dispersion: 208.39 ms
Peer dispersion: 9.63 ms
Reference time: 17:03:32.022 UTC Thu Sep 6 2001 (BF422AE4.05AEA86C)
The output information indicates that Switch 7750-1 is synchronized to Switch
7750-3, with the clock stratum being 3, one stratum higher than Switch 7750-3.
# View the information about the NTP sessions of Switch 7750-1 and you can see
that a connection is established between Switch 7750-1 and Switch 7750-3.
[Switch 7750-1] display ntp-service sessions
source reference stra reach poll now offset delay disper
**************************************************************************
[1]3.0.1.31 127.127.1.0 2 1 64 377 26.1 199.53 9.7
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured