Linksys Official Support - Connecting devices to a Linksys router using an Ethernet cable
Belkin Official Support - Cascading or Connecting a Belkin router to another router
How to Fix an Unstable Wi-Fi Connection: 6 Tips and Fixes
Wifi unstable and wan connection drops on Xiaomi MI router 4c on SoC MediaTek MT7628AN running on OpenWrt 21.02.0-rc2 stable release · Issue #547 · openwrt/mt76 · GitHub
My ISP's original router worked with an ADSL, now I bought a new TPLink router which works using WAN and doesn't recognize the ADSL, what should I do? - Quora