3com 5500-ei pwr Guía De Referencia

 

1-9 

Use the undo vrrp vrid preempt-mode command to cancel the configuration, that is, configure the 

switch to work in the non-preemptive mode. 

By default, switches in a VRRP group operate in the preemptive mode, with the preemption delay 

period set to 0 seconds. 

If you want a switch with high priority to preempt the master, configure the switch to operate in the 

preemptive mode. You can also set the delay period for preemption as needed. 

For 5500-EI series, you can enable the preemptive mode for switches in a VRRP group: 

z 

In a VRRP group where the preemptive mode is not enabled, once a switch in the VRRP group 

becomes the master, other switches, even if they are with a higher priority later, do not preempt the 

master as long as the master is not down. 

z 

In a VRRP group where switches are enabled with the preemptive mode, a backup sends out 

VRRP advertisements to trigger a new master election if it finds its priority is higher than that of the 

current master, and finally becomes the new master. The former master becomes a backup 

accordingly. 

You can also set the preemptive delay for the switches in a VRRP group. Setting a preemption delay 

period aims at:  

z 

In an unstable network, backups in a VRRP group possibly cannot receive VRRP advertisements 

from the master in time due to network congestions. This causes the master of the VRRP group to 

be determined frequently. In this case, the backup considers itself as the master and sends out 

VRRP advertisements to elect the master. This causes the master of the VRRP group to be 

determined frequently. 

z 

With the configuration of preemption delay, if a backup does not receive VRRP advertisements 

from the master in time, it waits for a while before switching to a new master. The backup does not 

send VRRP advertisements if it receives VRRP advertisements from the master during the 

specified delay period. 

# Configure the switch to operate in the preemptive mode. 

<Sysname> system-view  

System View: return to User View with Ctrl+Z. 

[Sysname] interface Vlan-interface 2 

[Sysname-Vlan-interface2] vrrp vrid 1 preempt-mode 

# Set the preemption delay period. 

[Sysname-Vlan-interface2] vrrp vrid 1 preempt-mode timer delay 5 

# Configure the switch to operate in non-preemptive mode. 

[Sysname-Vlan-interface2] undo vrrp vrid 1 preempt-mode 

vrrp vrid virtual-router-id priority priority 

undo vrrp vrid virtual-router-id priority 

VLAN interface view