3Com SuperStack 4 Configuration Manual page 356

368 C 12: F S
HAPTER ILE
Configure NTP Multicast
Mode
M
YSTEM ANAGEMENT
In the above examples Switch 4 and Switch 1 are configured to listen to the
broadcast via Vlan-interface2, Switch 3 to broadcast packets from Vlan-interface2.
As Switch 1 and Switch 3 are not located on the same segment, they cannot
receive any broadcast packets from Switch 3, while Switch 4 is synchronized by
Switch 3 after receiving its broadcast packet.
3 After the synchronization, you can find the state of Switch 4 as follows:
[switch4]display ntp-service status
clock status: synchronized
clock stratum: 3
reference clock ID: LOCAL(0)
nominal frequency: 100.0000 Hz
actual frequency: 100.0000 Hz
clock precision: 2^17
clock offset: 0.0000 ms
root delay: 0.00 ms
root dispersion: 10.94 ms
peer dispersion: 10.00 ms
reference time: 20:54:25.156 UTC Mar 7 2002(C0325201.2811A112)
By this time, Switch 4 has been synchronized by Switch 3 and it is at stratum 3,
higher than Switch 3 by 1.
Display the status of Switch 4 sessions and you will see Switch 4 has been
connected to Switch 3.
[switch2]display ntp-service sessions
source
********************************************************************
[12345]127.127.1.0 LOCAL(0) 7 377 64
[5]1.0.1.11
[5]128.108.22.44
note: 1 source(master),2 source(peer),3 selected,4 candidate,5
configured
Network Requirements
Switch 3 sets the local clock as the master clock at stratum 2 and multicast packets
from Vlan-interface2. Set Switch 4 and Switch 1 to receive multicast messages
from their respective Vlan-interface2. Networking Diagram
See Figure 94.
Configuration Procedure
Configure Switch 3:
1 Enter System View.
<switch3> system-view
2 Set the local clock as a master NTP clock at stratum 2.
[switch3]ntp-service refclock-master 2
3 Enter Vlan-interface2 view.
[switch3]interface vlan-interface 2
4 Set it as a multicast server.
reference stra reach poll
0.0.0.0 3 0
0.0.0.0 16 0
now offset delay disper
57 0.0 0.0
64 - 0.0 0.0
64 - 0.0 0.0
1.0
0.0
0.0