Cisco ASA 5505 Failover Active/Standby Configuration

Here is the quick configuration command

On Active Unit

failover
failover lan unit primary
failover lan interface fo Vlan3
failover interface ip fo 10.0.0.1 255.255.255.252 standby 10.0.0.2
 
interface Ethernet0/6
 switchport access vlan 3

Secondary Configuration

failover
failover lan unit secondary
failover lan interface fo Vlan3
failover interface ip fo 10.0.0.1 255.255.255.252 standby 10.0.0.2

Force the current unit to go on standby mode

no failover active

You got to understand how failover works as this is just a quick config on Cisco ASA

Enjoy!