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Hi, I have a Archer C7 V2 provided by Dutch ISP Ziggo. I have flashed Firmware ziggoFW-to-tplink-150427.bin so that all features of the router are reachable. (Firmware of Ziggo only gives acces to AP setup, not USB and other features).
That seems to work because I can use the Web-interface of the C7, but I have a problem with setting up LAN configuration.

My WAN connection is trough an ISP-modem (Compal Broadband Modem/router) which gives my home-network an IP-range of 192.168.178.10 to 192.168.178.254 with a subnet of 255.255.255.0
I want to connect the C7 as an AccesPoint using the same IP-range of main router so I can Use the C7 as a WIFI extender with the same SSID but also network acces to my USB external drive.
I hope this is clear to you.
When I want to setup the C7 through the Web-interface of the C7 I cannot setup the LAN-ip address. The WAN-connection is detected as Dynamic and when I try to set op LAN-IP as 192.168.178.227 (the IP address which was used when I setup C7 as AP from the ISP) I get an errormessage that IP and subnet cannot be the same as those from WAN or an error like invalid IP.
I disabled DHCP on the C7, C7 connected to PC with LAN-port 1 (Yellow).
For Connection to the internet I Use the WAN-port (Blue).
Can anyone help me to setup the C7 as AccesPoint which uses the same network as my home-network?