Most corporate network devices like Cisco will reset their config to the one written in memory when they lose power.

So in that case, just unplug and replug them to restore to previous config.

Just make sure you write your new config to memory or it will reset when there is ever a power failure.

So I connected through ssh back home to fiddle with the router settings, and in the PPPoE settings (where you set a pair of username and password that your router sends to the ISP such that the ISP knows you and knows what IP to assign to you) I made a typo, and apparently that instantly killed the internet connection at home and also for me. I had to call my mom to instruct her to fix the typo in the username. TBH I don't know that much about PPPoE either, I only do it so that the ISP assigns us the same IP address every time.