101
4.
Configure NTP authentication on Device A:
# Enable NTP authentication.
[DeviceA] ntp-service authentication enable
# Set an authentication key, and input the key in plain text.
[DeviceA] ntp-service authentication-keyid 42 authentication-mode md5 simple
aNiceKey
# Specify the key as a trusted key.
[DeviceA] ntp-service reliable authentication-keyid 42
5.
Verify the configuration:
# Verify that Device B has synchronized to Device A, and the clock stratum level is 3 on Device B
and 2 on Device A.
[DeviceB] display ntp-service status
Clock status: synchronized
Clock stratum: 3
System peer: 1.0.1.11
Local mode: client
Reference clock ID: 1.0.1.11
Leap indicator: 00
Clock jitter: 0.005096 s
Stability: 0.000 pps
Clock precision: 2^-10
Root delay: 0.00655 ms
Root dispersion: 1.15869 ms
Reference time: d0c62687.ab1bba7d Wed, Dec 29 2010 21:28:39.668
# Verify that an IPv4 NTP association has been established between Device B and Device A.
[DeviceB] display ntp-service sessions
source reference stra reach poll now offset delay disper
********************************************************************************
[1245]1.0.1.11 127.127.1.0 2 1 64 519 -0.0 0.0065 0.0
Notes: 1 source(master),2 source(peer),3 selected,4 candidate,5 configured.
Total sessions: 1
Configuration example for NTP broadcast mode
with authentication
Network requirements
As shown in
, Router C functions as the NTP server for multiple devices on different network
segments and synchronizes the time among multiple devices. Router A and Router B authenticate the
reference source.
•
Configure Router C's local clock as a reference source, with the stratum level 3.
•
Configure Router C to operate in broadcast server mode and send broadcast messages from
GigabitEthernet 2/0/1.
•
Configure Router A and Router B to operate in broadcast client mode and receive broadcast client
through GigabitEthernet 2/0/1.
