I am not an expert in this matter. I don't know much about technology, but I think it's the IP address. The correct IP Address to log into your router is the one that ends with 1.1. Very often people get confused and type in the letters at the end. That's why it often fails to log in and connect. You can read more information about 192.168.1.1 on the Internet

I see this IP quite often too and to be honest I don't know what it is because I don't know anything about it but if you do want to know what it is I suggest you watch a couple of videos on youtube.