Cannot admin gateway via wired connection

I went on vacation and had to reset my mobile device network to be able to use the partner networks. When I came home I needed to log back into the gateway Wi-Fi, but I stored my encrypted passwords on a computer that has stopped working. So I connected to the gateway via wired on a system that has no wireless connection and tried to admin the gateway. This is not possible to do. How could they lock out admin service from a wired connection? This just seems like the programmers didn't want the wired ports to be used. Just to clarify, I use encrypted passwords on different devices and try not to have multiple passwords for a single device on the same managers. So my admin password was available to me via the phone, but not the Wi-Fi. 
 

So I have to reset my gateway and restart the install process, reconnect all my devices and waste hours of my time when it could have been easily resolved with a better interface. What a rotten way to end a nice vacation.