You can upgrade directly to the desired version. Check "Upgrading the Software"
I would strongly recommend to find a supported version since 9.1 is going EOL.
If you have any questions, let us know.
I have to upgrade a couple of our ASA 5550 firewalls from 8.4(7) to 9.1(7).
Have you heard about this critical security advisory: Cisco Adaptive Security Appliance Remote Code Execution and Denial of Service Vulnerability
9.1(7) is an affected release. The fix for this version is found in 9.1(7)23.
I did I have already upgraded four of our firewalls to mitigate this vulnerability.
But the rest of them has a 8.4.7 running on them which is a major upgrade. That is why I would like to know about the configuration changes while upgrading from 8.4.7 to 220.127.116.11.
Your help would be much appreciated.
The firewalls that I am planning to upgrdae are IPSec firewalls. I checked for IPV6 config and traffic, there isn't any. So IPV6 is not a problem anymore.
I am worried about the Certificates, do they change when I perform the upgrade?
Your comments would be much appreciated.