networking - Expanding wireless coverage: What are the differences between LAN to LAN and LAN to WAN when it comes to connecting two wireless routers? - Super User
Application Requirement/Choose WAN Connection Type on my TP-Link router
Can I connect 1 wifi router to another using LAN cable to increase the area of wifi signal? - Quora
Feeling clueless about Wi-Fi and home networking? Here's where you start. - CNET