So I recently found out the hard way that reverting back to an earlier/older EdgeRouter firmware image also reverts back to the configuration at the time of upgrade to the newer firmware. I expected the current (latest) configuration to remain active regardless of which firmware version you're running. In my case the router was upgraded to the 2.0.x firmware in our lab, before all production configuration was configured. When troubleshooting an issue I decided to downgrade the firmware just to confirm that this wasn't a result of a possible bug in the 2.0.x firmware. After reverting to the 1.10.x firmware I lost remote access to the router. When connecting to the console port I managed to log in and concluded that the settings ware as they ware at the time of the upgrade to the 2.0.x firmware. Luckily I made a back-up before reverting to the previous firmware so I was able to recover to the production configuration quickly.
username@router:~$ set system image default-boot
The system currently has the following image(s) installed:
v2.0.9-hotfix.2.5402463.210511.1317 (running image) (default boot)
v1.10.7.5127989.181001.1228
Are you sure you want to switch images? (Yes/No) [Yes]: Yes
Moving images...
Done
Switched from
Version: v2.0.9-hotfix.2.5402463.210511.1317
to
Version: v1.10.7.5127989.181001.1228
username@router:~$ reboot
Proceed with reboot? [confirm][y]
I thought this might be a word of caution to my peers :)