3com 8807 User Guide

C

HAPTER

 66: NTP C

ONFIGURATION

Designate an interface on the local Switch to receive NTP multicast messages and 
operate in multicast client mode. The local Switch listens to the multicast from the 
server. When it receives the first multicast packets, it starts a brief client/server 
mode to switch messages with a remote server for estimating the network delay. 
Thereafter, the local Switch enters multicast client mode and continues listening to 
the multicast and synchronizes the local clock by the multicast message that 
arrived.

Perform the following configuration in VLAN interface view.

Multicast IP address ip-address defaults to 224.0.1.1; this command can only be 
configured on the interface where the NTP multicast packets will be received. 
Actually, for the Switch 8800 Family series, you can set 224.0.1.1 as the multicast 
IP address only.

Enable NTP authentication, set MD5 authentication key, and specify the reliable 
key. A Client will synchronize itself by a server only if the serve can provide a 
reliable key.

Perform the following configuration in system view.

This configuration task is to set NTP authentication key.

Perform the following configuration in system view.

Key number number ranges from 1 to 4294967295; the key value contains 1 to 
16 ASCII characters.

This configuration task is to set the specified key as reliable.

Perform the following configuration in system view.

Table 704   Configure NTP multicast client mode

Configure NTP multicast client mode 

ntp-service multicast-client [ ip-address ] 

Cancel NTP multicast client mode 

Table 705   Configure NTP authentication

Enable NTP authentication 

ntp-service authentication enable 

Disable NTP authentication 

Table 706   Configure NTP authentication key

Configure NTP 
authentication key 

ntp-service authentication-keyid number 
authentication-mode md5 value 

Remove NTP 
authentication key 

undo ntp-service authentication-keyid number