Changing the link monitor failover threshold

Changing the link monitor failover threshold

If you have multiple link monitors you may want a failover to occur only if more than one of them fails.

For example, you may have 3 link monitors configured on three interfaces but only want a failover to occur if two of the link monitors fail. To do this you must set the HA priorities of the link monitors and the HA pingserver- failover-threshold so that the priority of one link monitor is less than the failover threshold but the added priorities of two link monitors is equal to or greater than the failover threshold. Failover occurs when the HA priority of all failed link monitors reaches or exceeds the threshold.

For example, set the failover threshold to 10 and monitor three interfaces:

config system ha

set pingserver-monitor-interface port2 port20 vlan_234 set pingserver-failover-threshold 10

set pingserver-flip-timeout 120 end

Then set the HA priority of link monitor server to 5.

The HA Priority (ha-priority) setting is not synchronized among cluster units. In the fol- lowing example, you must set the HA priority to 5 by logging into each cluster unit.

config system link-monitor edit port2

set server 192.168.20.20 set ha-priority 5

next

edit port20

set server 192.168.20.30 set ha-priority 5

next

edit vlan_234

set server 172.20.12.10

set ha-priority 5 end

If only one of the link monitors fails, the total link monitor HA priority will be 5, which is lower than the failover threshold so a failover will not occur. If a second link monitor fails, the total link monitor HA priority of 10 will equal the failover threshold, causing a failover.

By adding multiple link monitors and setting the HA priorities for each, you can fine tune remote IP monitoring.

For example, if it is more important to maintain connections to some networks you can set the HA priorities higher for these link monitors. And if it is less important to maintain connections to other networks you can set the HA priorities lower for these link monitors. You can also adjust the failover threshold so that if the cluster cannot connect to one or two high priority IP addresses a failover occurs. But a failover will not occur if the cluster cannot connect to one or two low priority IP addresses.