3com 8807 User Guide

C

HAPTER

 53: VRRP C

ONFIGURATION

In a network under possible security threat, the authentication type can be set to 
simple. Then the switch will add the authentication key into the VRRP packets 
before transmitting it. The receiver will compare the authentication key of the 
packet with the locally configured one. If they are the same, the packet will be 
taken as a true and legal one. Otherwise it will be regarded as an illegal packet to 
be discarded. In this case, an authentication key not exceeding 8 characters should 
be configured.

In a totally unsafe network, the authentication type can be set to md5. The switch 
will use the authentication type and MD5 algorithm provided by the 
Authentication Header to authenticate the VRRP packets. In this case an 
authentication key not exceeding 8 characters should be configured.

Those packets failing to pass the authentication will be discarded and a trap 
packet will be sent to the network management system.

Perform the following configuration in VLAN interface view.

The authentication key is case sensitive.

n 

The Master switch advertises its normal operation state to the switches within the 
VRRP virtual router by sending them VRRP packets regularly (at adver-interval). 
And the backup switch only receives VRRP packets. If the Backup has not received 
any VRRP packet from the Master after a period of time (specified by 
master-down-interval), it will consider the Master as down, and then take its place 
and become the Master.

You can use the following command to set a timer and adjust the interval, 
adver-interval, between Master transmits VRRP packets. The master-down-interval 
of the Backup switch is three times that of the adver-interval. The excessive 
network traffic or the differences between different switch timers will result in 
master-down-interval timing out and state changing abnormally. Such problems 
can be solved through prolonging the adver-interval and setting delay time. 
adver-interval is measured in seconds.

Perform the following configuration in VLAN interface view.

Table 598   Configure authentication type and authentication key

Configure authentication type and 
authentication key 

vrrp authentication-mode 
authentication-type authentication-key 

Remove authentication type and 
authentication key 

Table 599   Configure virtual router timer

Configure virtual router timer 

vrrp vrid virtual-router-ID timer advertise 
adver-interval