FortiAuthenticator

[koval]

Has anyone ever downgraded FAC from 5.5.0 to 4.3 build 8007?  

[cbabfat]

Technically, No, but it depends what you are trying to do and willing to lose.

A "downgrade" is really a image with the old operating system and restore the backup file.  If you just upgraded, then you are not going to lose anything by putting the old OS back on it and restoring from the backup file you made.  I went through this when 5.0 was messed up when it first came out.  I was particularly mad because we waited a few business days on support thinking they might fix it or "downgrade".  Come to find out downgrade is re-image and restore.  At least that was my experience.

Chris

[koval]

Thank you Chris.  We have directed by Fortinet to downgrade from 5.5 to 4.3. We are experiencing multiple issues - HA fail-over not working and chronic time adjust issue on Primary.  Were your issues similar?

[xsilver_FTNT]

Yes I did many times in lab. And as Chris wrote, downgrade is revert of the OS back, without config 'downgrade' routines. It's not supported.

But best practice of every upgrade says .. BACKUP before attempt .. so you should have backup config to restore.

Therefore it is supposed to be pretty straightforward .. restore OS and restore old/pre-upgrade config.

That's it.