H3C Technologies H3C S7500E Series Switches - Manual (Page 88)

3-24
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 A has been synchronized to Switch C, and the clock stratum level of
Switch A is 3, while that of Switch C is 2.
# View the NTP session information of Switch A, which shows that an association has been set
up between Switch A and Switch C.
[SwitchA-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 32.0 16.6
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations : 1
Configuring NTP Multicast Mode
Network requirements
As shown in Figure 3-10 , Switch C functions as the NTP server for multiple devices on different
network segments and synchronizes the time among multiple devices. To realize this
requirement, perform the following configurations:
z Switch C’s local clock is to be used as a reference source, with the stratum level of 2.
z Switch C works in the multicast server mode and sends out multicast messages from
VLAN-interface 2.
z Switch A and Switch D work in the multicast client mode and receive multicast messages
through VLAN-interface 3 and VLAN-interface 2 respectively.
Figure 3-10 Network diagram for NTP multicast mode configuration
Configuration procedure
1) Configure IP addresses for interfaces (omitted).
2) Configuration on Switch C:
# Specify the local clock as the reference source, with the stratum level of 2.
system-view
[SwitchC] ntp-service refclock-master 2