I have two DD-WRT routers in different locations. One of them is running the VPN version of the firmware, and the other is running the standard version. I am on location with the VPN one, and I want to upgrade the other one to run the VPN firmware so I can wire them together. Is this possible or advisable? Of course, I don't want to lose the settings on the remote one, since then I would lose my remote access (currently through SSH) and not be able to configure it.
I can't rule out the possibility of doing it but I can make some points against it.
- The recommended process (strongly reiterated by DD-WRT) involves a series of 'hard' resets that involve power cycling while holding down the physical reset button on the router. Tricky to do remotely :)
- Saved settings for one version of the firmware should NEVER be used with a different version.
I can say from personal experience that I have nearly bricked my router trying to upgrade DD-WRT over the web interface via remote connections. I would strongly recommend being physically connected to the router and having physical access.
The hard reset procedure that is officially recommended also comes in handy if anything goes wrong.