Road Runner Guide to the Internet

DD-WRT Dual Wan Guide v1.4
*updated* 11/28/09
WRT54G Supported


the following guides will show u how to convert an ordinary linksys router into a powerful dual wan firewall/router with failover support, load balancing, and a host of other features at the cost of next to nothing. other router manufacturers can be converted into dual wan but this guide only supports the linksys models listed below. if u want to use a different router, verify that it is supported, & visit this thread for possible help and remember to thank jbarbieri for all his hard work.

so what is a dual wan router & why is it so special? the idea is simple. its a router that allows the use of two seperate internet connections, thus doubling the available bandwidth while also providing a backup internet solution in case one modem dies. cool huh? so why doesnt everybody have a dual wan router, sounds easy? well its not, and because they cant. theres many reasons why but cost is number one.

 static wan ips are currently not supported, only wan ips acquired via dhcp. keep in mind you will not see any increase in speed if a typical speedtest is run or normal web browsing. u will only be able to fully utilize this type of dual wan when using download managers, torrents, or similar method that uses multiple threads to download/upload data. while it is possible to "double" the bandwidth typical results will be around 15-25% less the maximum depending on method chosen. true dual wan or bonding can only be accomplished with assistance from ur local isp.

Required Hardware & Software:

Setup The Hardware:

  • use a splitter and connect the two coax lines to the modems
  • using cat5, connect one modem to the internet port & the other to lan-4
  • connect the third cat5 cable to lan-1 and the other end to ur computer.
  • only power up the first modem thats connected to the internet port
  • leave the second modem connected to lan-4 off untill guide is complete.

Installation Methods & Iimitaions: [JFFS vs NVRAM]

  • NVRAM: this is a very quick and relatively easy method to enable dual wan but does not perferm as well as the JFFS method. you must first verify there is enough room in ur routers "nvram" to work correctly. telnet into ur router and enter "nvram show" then look at the last line. it needs to say atleast 6300 left.

  • JFFS: *dual wan kit required* this method does not use the routers nvram to store the scripts and instead stores the scripts in a jffs folder within the router itself. dual wan performance is much more stable and responsive using this method but its more difficult to setup and requires atleast 190kb of free jffs space to execute the dual wan scripts. many routers simply do not have enough memory to enable jffs and must resort to using the nvram method.

Choose Linksys Router:

Testing & Troubleshooting: