Running SDN network using openwrt firmware
Default TP-Link router internal diagram (from wiki.openwrt.org):

Create OVS and connect lan2,3,4 and WiFi. Keeping lan1 for OF controller (Recommended settings)

It will completely replace br-lan with OVS and connect all ports to the OVS.
With this sittings, if you missed up things, then you have to reset the router or use Serial port.

Upgrade TP-Link AC1750 C2 V2 to OpenWRT 15.05 which include OVS switch, or install OVS if you have OpenWRT on your router.
SSH into your tplink router ( ssh root@192.168.1.1) Make sure WiFi is up. Copy this script into ovsbr.sh file and then past it there (vim ovsbr.sh ), press (i), right click -> past, then press (esc), then (:wq). Add run permission chmod +x ovsbr.sh Then run the script ./ovslan.sh Before answering replace 'br-lan', please read check the diagram above and read the instructiosn.