Convert a Router to a Switch

I have an Asus RT-N16 running Tomato in my basement. The signal strength outside the house is quite poor.
Also I do a lot of my tinkering with dev boards upstairs in my study. A lot of the dev board use ethernet and not wifi. To that end I decided to re-purpose an old Dlink WBR-1310 router as a switch and wifi range extender.

It took me a few tries to get it right! On the Dlink:

  1. Disable DHCP
  2. Disable UPnP
  3. Disable Gaming Mode 
  4. Change Dlink's IP to be OUTSIDE the DHCP range of the Asus Router. This is important. My Asus router was at and was handing out IP's from 100-129 so I set my Dlink IP to be
  5. Connect ethernet cable from Asus LAN port to Dlink LAN port. Nothing is connected to the Dlink WAN port
  6. Setup Wifi with new SSID and password

The DLink is not Gigabit like the Asus but that's ok since I'll be using the dlink for connecting my dev board and for browsing over a table or phone while I'm sitting outside at the pool. My NAS and HTPC are hardwired into the gigabit Asus.