H3C Technologies H3C S7500E Series Switches - Manual (Page 86)

3-22
3) Configuration on Device B:
# Specify Device A as the NTP server of Device B.
system-view
[DeviceB] ntp-service unicast-server 3.0.1.31
4) Configuration on Device C (after Device B is synchronized to Device A):
# Specify the local clock as the reference source, with the stratum level of 1.
system-view
[DeviceC] ntp-service refclock-master 1
# Configure Device B as a symmetric peer after local synchronization.
[DeviceC] ntp-service unicast-peer 3.0.1.32
In the step above, Device B and Device C are configured as symmetric peers, with Device C in
the symmetric-active mode and Device B in the symmetric-passive mode. Because the stratus
level of Device C is 1 while that of Device B is 3, Device B is synchronized to Device C.
# View the NTP status of Device B after clock synchronization.
[DeviceB] display ntp-service status
Clock status: synchronized
Clock stratum: 2
Reference clock ID: 3.0.1.33
Nominal frequency: 100.0000 Hz
Actual frequency: 100.0000 Hz
Clock precision: 2^18
Clock offset: -21.1982 ms
Root delay: 15.00 ms
Root dispersion: 775.15 ms
Peer dispersion: 34.29 ms
Reference time: 15:22:47.083 UTC Sep 19 2005 (C6D95647.153F7CED)
As shown above, Device B has been synchronized to Device C, and the clock stratum level of
Device B is 2, while that of Device C is 1.
# View the NTP session information of Device B, which shows that an association has been set
up between Device B and Device C.
[DeviceB] display ntp-service sessions
source reference stra reach poll now offset delay disper
**************************************************************************
[245] 3.0.1.31 127.127.1.0 2 15 64 24 10535.0 19.6 14.5
[1234] 3.0.1.33 LOCL 1 14 64 27 -77.0 16.0 14.8
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations : 2
Configuring NTP Broadcast Mode
Network requirements
As shown in Figure 3-9 , Switch C functions as the NTP server for multiple devices on a network
segment 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 broadcast server mode and sends out broadcast messages from
VLAN-interface 2.