I have three ASA5520 with AIP-20 modules all with active licenses. Originally I had two in an HA Active/Standby configuration. Unfortunately during our Data Center move one of the firewall was damaged and would not boot. I purchased a replacement but I made a mistake on the software and realized it too late to do an exchange. The unit came with a CSC module, the original two came with an IPS module. I was trying to setup the HA failover but the software would not allow me to due to a mismatch. What can I do to get the software problem corrected? Can I just remove the AIP-20 modules on both since I don't use them anyway and try to setup failover without it? Both ASA are running the same code and revision so the only thing I see is the added software. What is weird is that I took the AIP-20 module from the old one which was in the A/S pair and was not booting into the newly purchased unit and that unit still came up with the CSC software. So it seems the AIP-20 modules are just generic and its the license/software that I need changed?
CSC module and AIP module are 2 different modules, and to run ASA in failover mode, you would need to have the same module installed on both ASA.
CSC - Content Security and Control module - protection against virus, spyware, spam, etc for SMTP, POP3, FTP and HTTP traffic
AIP - Advanced Inspection and Prevention module - the normal IPS module
As mentioned, if you don't need to have the module, you can take it out and run the ASA in failover as long as the ASA is the same model, version and has the same license installed.
Here is the requirement to run failover: