H3C Technologies H3C S7500E Series Switches - Manual (Page 92)

3-28
Reference clock ID: 1.0.1.11
Nominal frequency: 100.0000 Hz
Actual frequency: 100.0000 Hz
Clock precision: 2^18
Clock offset: 0.0000 ms
Root delay: 31.00 ms
Root dispersion: 1.05 ms
Peer dispersion: 7.81 ms
Reference time: 14:53:27.371 UTC Sep 19 2005 (C6D94F67.5EF9DB22)
As shown above, Device B has been synchronized to Device A, and the clock stratum level of
Device B is 3, while that of Device A is 2.
# View the NTP session information of Device B, which shows that an association has been set
up Device B and Device A.
[DeviceB] display ntp-service sessions
source reference stra reach poll now offset delay disper
**************************************************************************
[12345] 1.0.1.11 127.127.1.0 2 63 64 3 -75.5 31.0 16.5
note: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured
Total associations : 1
Configuring NTP Broadcast Mode with Authentication
Network requirements
As shown in Figure 3-12 , 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 and ensure network security, perform the following configurations:
z Switch C’s local clock is to be used as a reference source, with the stratum level of 3.
z Switch C works in the broadcast server mode and sends out broadcast messages from
VLAN-interface 2.
z Switch D works in the broadcast client mode and receives broadcast messages through
VLAN-interface 2.
z NTP authentication is enabled on both Switch C and Switch D.
Figure 3-12 Network diagram for configuration of NTP broadcast mode with authentication
Vlan-int3
1.0.1.11/24 Vlan-int3
1.0.1.10/24
Vlan-int2
3.0.1.31/24
Vlan-int2
3.0.1.32/24
Vlan-int2
3.0.1.30/24
Switch A Switch B
Switch C
Switch D