asa ha standby ip

[mkazam001]

Hi All,

Can someone explain how the ASA uses the standby IP in a Active/Standby config. I have always configured the devices like this as per cisco design. Tried to look into this further but unable to find a definitive answer. When the PRIMARY fw fails, the Secondary uses the IP & MAC of the of the PRI - so how does it use the standby IP configured on the interface?

Regards, mk

[GRANT3779]

Two things come to mind.
You would use a standby address on a management related port so you can actually manage the secondary firewall. How else would you be able to SSH to it for example?
Also, for the purposes of monitoring as part of your HA setup. The standby ip is used by the active ASA to monitor the secondary firewalls interface if that interface is part of your failover monitoring config.

[GRANT3779]

Should add, for management - if you are not using OOB or dedicated management port