@Kevin_Z I tried that configuration but it not even connect to my C2. DHCP not work cannot get IP from main router, after set static IP cannot ping to C2.

After I tested more I found that. I don't need to enable WDS on td-w8961nd to make local connection work on td-w8961nd. I still not able to connect to internet. I found that adding some static route...

I using C2 as access point connect to the main router via wired network for many year. I leave the WAN connection down and use only the land port to the main router. I would like to expand the...