We just recently put in a failover ASA 5520/IPS SSM-20. I'm trying to upgrade it to the same version as the primary, 5.1(5)-E1, however, when I attempt to go from 5.0(2), it doesn't let me. So I tried to go from 5.0(2) to 5.1(3), but get this when I try:
sensor# config t
sensor(config)# upgrade ftp://10.x.x.x/IPS-K9-sp-5.1-3.pkg
Warning: Executing this command will apply a service pack to the application partition. The system may be rebooted to complete the upgrade.
Continue with upgrade? : yes
Error: execUpgradeSoftware : This doesn't seem like a nice ftp-server response
I don't know where to go from here, please help.