Multiple ethernet connections and one shows "Not installed"

[chefebe]

I have a 412+. I connected 2 ethernet cables. I configured one of them in the Synology Assistant and it now shows "Ready". The 2nd ethernet connection shows "Not installed". When I go to configure it, I am told that "everything on the hard drives will be erased." I've already started to load the NAS with a lot of content. Why does the 2nd ethernet connection configuration need to erase the disks again to setup?

I do not yet have a switched hub so the 2nd connection if probably pointless (I'm new to this). I do plan add a switched hub for better bandwidth mainly as I am planning to add surveilance in the coming months. Inside Control Panel, Network, Network Interface, it shows both connections as "Connected".

The question is whether I should configure the 2nd network connection now so that I won't have to erase all the hard disks in a few months when I need the 2nd connection and my NAS is harder to backup/restore.

Thanks for any guidance.
Bob