Table 11 Configuration items

Item

Description

Clock status

Display the synchronization status of the system clock.

 

 

 

 

 

 

 

Source Interface

Set the source interface for an NTP message.

 

This configuration makes the source IP address in the NTP messages the

 

primary IP address of this interface. If the specified source interface is

 

down, the source IP address is the primary IP address of the egress

 

interface.

 

 

 

 

 

 

TIP:

 

 

 

 

 

 

 

 

 

 

 

 

 

If you do not want the IP address of an interface on the local device to

 

become the destination address of response messages, specify the

 

source interface for NTP messages.

 

 

 

 

 

 

 

Key 1

Set NTP authentication key.

 

Enable the NTP authentication feature for a system running NTP in a

Key 2

 

network that requires high security. This feature improves the network

 

security by means of client-server key authentication, and prohibits a

 

client from synchronizing with a device that has failed authentication.

 

You can set two authentication keys, each of which has a key ID and a

 

key string.

 

ID—ID of a key.

 

Key string—Character string of the MD5 authentication key.

External

NTP Server

Reference

1/Reference

Source

Key ID.

 

 

 

NTP Server

 

2/Reference

 

Key ID.

Specify the IP address of an NTP server, and configure the authentication key ID used for the association with the NTP server. The device synchronizes its time to the NTP server only if the key provided by the server is the same as the specified key.

You can configure two NTP servers. The clients choose the optimal reference source.

IMPORTANT:

The IP address of an NTP server is a unicast address, and cannot be a broadcast or a multicast address, or the IP address of the local clock source.

System time configuration example

Network requirements

As shown in Figure 48:

The local clock of Device A is set as the reference clock.

Switch B operates in client mode, and uses Device A as the NTP server.

Configure NTP authentication on Device A and Switch B so that Switch B is to be synchronized to Device A.

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