I want to connect a second wireless routre upstairs to primary wireless router downstaire via cat6 cable for better coverage. My primary wireless router is from Xfinity ( dual-band WiFi 802.11ac) I 've watched numerous YouTube video's, took lots of notes and thought I was ready to start connecting. When I started looking for the I.P address of primary rounter, the IP didn't look like one I'm fimilur with. As you know, I need the IP address to go into the router setting via my browser. I've had Xfinity here numerous times and they only setup wifi boosters that didn't work. WiFi was very spotty at best
What's the make of your secondary router? Typically, most will allow you to set them up in AP mode or Wireless Access Point mode once you hook up the ethernet cables so you don't need to fumble around with manual configuration.
But to answer your pirmary question, the typical Xfinity Gateway will have its IP address at http://10.0.0.1 unless it's been changed.