I use my old router (wdr3600) as simple switch for 2 devices to share the same LAN cable. All 3 cables, including uplink to main router are connect to LAN ports on wdr3600. WAN port is not connected at all.
Switching on LAN works flawlessly, both devices see main router and use it as gateway full speed. Also main router is only DHCP, while in wdr3600 is it disabled on LAN interface.
My question now, how do I access wdr3600 Luci or ssh, while this router is not visible in main router. It does not have an IP. What if I just connect WAN port to another LAN port? That could work?
Why I need this? I don't need it right now but in case switching stop working, I need to find whats wrong and having access to Luci would be great.
Another option would be probably use different wifi but I dont want it pollute already crowded space.