3Com 3.01.01 Switch User Manual


 
Configuring VRRP 295
The delay ranges from 0 to 255, measured in seconds. The default mode is
preemption with a delay of 0 second.
Configuring
Authentication Type and
Authentication Key
To prevent unauthorized routes from joining the virtual router, a key can be
configured that is used in one of the following VRRP authentication types:
Simple character authentication — The authentication type is set to simple.
The switch adds the authentication key to the VRRP packets before
transmitting it. The receiver compares the authentication key of the packet to
the locally configured authentication key. If they are the same, the packet is
accepted as a true and legal. If the keys are not the same the packet is
considered illegal and is discarded. A simple authentication key should not
exceed 8 characters.
MD5 authentication — The authentication type is set to md5. The switch uses
the authentication type and MD5 algorithm, provided by the authentication,
header to authenticate VRRP packets. An md5 authentication key should not
exceed 16 packets that fail to pass the authentication test. If 16 fail they are
discarded and a trap packet is sent to the network management system.
Perform the following configuration in VLAN interface view.
The same authentication type and authentication key should be configured for all
vlan interfaces that belong to the virtual router.
Configuring the VRRP
Timer
The Master switch advertises its normal operation state to the switches within the
VRRP virtual router by sending them VRRP packets regularly, at the specified
advertised interval. If the backup switch does not receive a VRRP packet from the
master after a period of time (specified by master-down-interval), the master is
assumed to have failed and the backup switch takes the role of master.
You can use the following command to set a timer and adjust the interval,
adver-interval at which the master transmits VRRP packets. The duration of the
backup switch’s master-down-interval is three times the duration of the
adver-interval. Excessive network traffic or the differences between different
switch timers results in master-down-interval timing out and state changing
abnormally. Such problems can be solved through prolonging the adver-interval
and setting delay time. The duration of adver-interval is measured in seconds.
Perform the following configuration in VLAN interface view.
Table 6 Configure Authentication Type and Authentication Key
Operation Command
Configure the authentication type and
authentication key.
vrrp authentication-mode type [ key ]
Clear the authentication type and
authentication key.
undo vrrp authentication-mode
Table 7 Configure VRRP Timer
Operation Command
Configure VRRP timer vrrp vrid virtual-router-ID timer advertise
adver-interval