3Com 7757 Configuration Manual page 765

NTP Broadcast Mode
Configuration
n
<SW77503> system-view
[SW77503]
# After the local synchronization, set the Switch 7750 to be its peer.
[SW77503] ntp-service unicast-peer 3.0.1.32
The Switch 7750 and 3Com3 are configured to be peers with regard to each
other. 3Com3 operates in the active peer mode, while the Switch 7750 operates in
the passive peer mode. Because the stratum of the local clock of 3Com3 is 1, and
that of the Switch 7750 is 3, the Switch 7750 is synchronized to Qudiway3.
View the status of the Switch 7750 after the synchronization.
[SW7750] display ntp-service status
Service status: enabled
Clock status: synchronized
Clock stratum: 2
Reference clock ID: 3.0.1.32
Nominal frequency: 250.0000 Hz
Actual frequency: 249.9992 Hz
Clock precision: 2^19
Clock offset: 0.66 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 the Switch 7750 is synchronized to 3Com3
and the stratum of its local clock is 2, one stratum higher than 3Com3.
# View the information about the NTP sessions of the Switch 7750 and you can
see that a connection is established between the Switch 7750 and 3Com3.
[SW7750] display ntp-service sessions
source reference
**************************************************************************
[2]3.0.1.32 127.127.1.0
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Network requirements
3Com3 sets its local clock to be an NTP master clock, with the stratum being 2.
NTP packets are broadcast through VLAN interface 2.
Configure S7750-1 and S7750-2 to listen to broadcast packets through their
VLAN interface 2.
This example assumes that 3Com3 is a switch that supports the local clock being
the master clock.
Configuration Example
stra reach poll now offset
1 1 64 1 350.1
765
delay disper
15.1 0.0