I have a license to upgrade my ASA pair. The license appears to be associated with the serial number of the Secondary (though currently active) ASA. The question is - to input the new license and have it take effect on both members of the pair is there anything special that needs to be done? Just install the license on the secondary/active and this will replicate to the primary/standby? The instructions that came with the key are a little vague not mentioning on what to do with the bundle.
"Installing Your Cisco Adaptive Security Appliance Activation Key
Step 1. From the command line interface (CLI), enter configuration mode using
the "conf t" command.
Step 2. Type the "activation-key" command, and then, when prompted, enter the
new activation key listed above."
No, you would need to purchase exactly the same upgrade license for the other ASA (in your case, serial# of the primary).
If you just enter the activation key into the secondary active firewall, it will break (turn off) the failover automatically, because one of the requirement for failover to have exactly the same license on both ASA.
And, yes, you are right. License is tied to the serial# of the device, hence, if you have purchased the upgrade license for the secondary ASA serial#, you would need to purchase the same upgrade license for the primary ASA serial#.
Hope that helps.