3com S7906E Instruccion De Instalación

 

1-9 

For devices working in the symmetric mode, you need to specify a symmetric-passive peer on a 

symmetric-active peer. 

Following these steps to configure a symmetric-active device: 

Enter system view 

— 

Specify a symmetric-passive 
peer for the device 

ntp-service unicast-peer 
[ vpn-instance 
vpn-instance-name ] 
{ ip-address | peer-name } 
[ authentication-keyid keyid | 
priority | source-interface 
interface-type interface-number 
| version number ] * 

Required 

No symmetric-passive peer is 
specified by default. 

 

z 

In the symmetric mode, you should use the ntp-service refclock-master command or any NTP 

configuration command in 

 to enable NTP; otherwise, a 

symmetric-passive peer will not process NTP messages from a symmetric-active peer. 

z 

In the ntp-service unicast-peer command, ip-address must be a unicast address, rather than a 

broadcast address, a multicast address or the IP address of the local clock. 

z 

When the source interface for NTP messages is specified by the source-interface argument, the 

source IP address of the NTP messages will be configured as the primary IP address of the 

specified interface. 

z 

Typically, at least one of the symmetric-active and symmetric-passive peers has been 

synchronized; otherwise the clock synchronization will not proceed. 

z 

You can configure multiple symmetric-passive peers by repeating the ntp-service unicast-peer 

command. 

 

The broadcast server periodically sends NTP broadcast messages to the broadcast address 

255.255.255.255. After receiving the messages, the device working in NTP broadcast client mode 

sends a reply and synchronizes its local clock. 

For devices working in the broadcast mode, you need to configure both the server and clients. Because 

an interface needs to be specified on the broadcast server for sending NTP broadcast messages and 

an interface also needs to be specified on each broadcast client for receiving broadcast messages, the 

NTP broadcast mode can be configured only in the specific interface view.