Set the DD-WRT based D-Link DIR-300 ver. B as a Repeater Bridge

Original link here: http://jgiam.com/2012/07/06/setting-up-a-repeater-bridge-with-dd-wrt-and-d-link-dir-600/wp-admin/install.php

Here are the steps I did (adapted from the DD-WRT Wiki). My primary router is configured with WPA2 AES. The secondary router is running DD-WRT build 14311. The latest build in the DD-WRT router database, build 14896, is buggy.

• Restore Factory Defaults on Secondary (DD-WRT) Router
• Connect your computer to the secondary router via wired LAN port.
• Open the address http://192.168.1.1 in your web browser. Newer versions of DD-WRT will require you to set a password before you can continue.
• Open the Wireless -> Basic Settings tab
  • Physical Interface Section
    • Wireless Mode : Repeater Bridge
    • Wireless Network Mode : Must Match Primary Router
    • Wireless Network Name(SSID) : Must Match Primary Router exactly including exact case- Make sure you spell this correctly
    • Wireless Channel : Must Match Primary Router (This will disappear once you put it in RB mode, and isn’t needed)
    • Wireless SSID Broadcast : Enable
    • Network Configuration : Bridged
  • Save
• Open the Wireless -> Wireless Security tab
  • Physical Interface Section
    • Security Mode : Must Match Primary Router and DD-wrt only works reliably with WEP or WPA2-AES
    • WPA Algorithms : Must Match Primary Router
    • WPA Shared Key : Must Match Primary Router
    • Key Renewal Interval (in seconds) : Leave default
  • Save
• Open the Setup -> Basic Setup tab
  • Connection Type will be: Disabled
  • Set STP for Disabled (Enabled sometimes can cause connection problems) redhawk
  • IP Address : 192.168.1.2 (Assuming Primary Router IP is 192.168.1.1)
  • Mask : 255.255.255.0
  • Gateway: 192.168.1.1 (again assuming Primary Router IP is 192.168.1.1)
  • DHCP Server: Disable
  • Local DNS: 192.168.1.1 (if IP of Primary Router is 192.168.1.1)
  • Assign WAN Port to Switch : Optionally enable this to use the WAN port as another LAN port.
  • Save
• Open Setup -> Advanced Routing tab
  • Set Operating mode to “Router”
  • Save
• Open Services
  • Disable Dnsmasq
  • Save
• Open the Security -> Firewall tab
  • Uncheck all boxes…except Filter Multicast
  • Disable SPI firewall
  • APPLY Settings
• Reboot the router.