How to Resurrect a Dead Linksys WRT54G Router Part1

One of the more exciting developments for networking enthusiasts has been the evolution of open-source firmware replacements for certain popular, inexpensive routers (usually the famed Linux-running Linksys WRT54G).




While replacement firmware offers the promise of significantly expanded features, greater customization and mondo-tweakability, it also carries some risk. Should misfortune strike, you might, oh, let’s say, render your router into a useless hunk of plastic. Or, as victims prefer to say, you could “brick it.” How does a router become a brick? And if it does, is there any hope of bringing it back to life?



The short answers: "by accident," and "yes... sometimes."



How a Router Becomes a Brick



Bricks are very good at holding up the walls of your house. Bricks are not very good at routing network traffic. You don’t want your router to suddenly become one. (Likewise, you don’t want the bricks in your walls to suddenly become routers – although that would be pretty cool, no?) But sometimes it happens. Often, you can avoid this fate by understanding how a router can become a brick.



There is an alchemy to turning a router into a brick. The most common formula is the bad flash. When you upgrade the firmware in your router, you’re basically swapping in a new brain in place of the old. This brain controls most of the router's cognitive functions.



The upgrade process, described in The Open Source WRT54G Story, can require up to two minutes. If "Something Bad" happens during this process – loss of power to the router, loss of network connectivity to the uploading PC – you may have just bricked your router.



When upgrading your firmware, try to prevent "Something Bad" from happening:



•Be sure the power source is secure.

•Only upgrade through a wired Ethernet connection; do not use a wireless connection.

•Be sure to manually configure the IP address on your uploading PC – do not rely on automatic DHCP address assignment.

•Be sure to disable any software firewall running on your uploading PC, including the Windows firewall.

RAM, Corrupted



Your router has a small amount of on-board NVRAM (define), or non-volatile memory. Sometimes your flash upgrade will be successful, but your NVRAM will become corrupted. Often, this happens when the firmware you uploaded to the router wasn’t exactly the right version for your model. Be sure to read the upgrade instructions for your chosen firmware very, very, very carefully.



For example, consider DD-WRT, one of the most popular open source firmware replacements for Linksys WRT series routers. DD-WRT is available in many flavors. There is a “minimal” build with only a base feature set. There is also a “generic” build which lacks optimizations, and some model-specific builds, among other variants.



When upgrading the router from the Linksys-branded firmware, you are supposed to “step up” by first installing the minimal DD-WRT build, and upgrading from there to a more feature-rich build.



However, when upgrading your router through DD-WRT’s Web interface, you're directed to use the generic build.



Trip up on one of these finer points, and your upgrade may appear successful at first. But then you configure the router, it reboots, and hello Brickville, city of bricks. Most likely, your “successful” flash upgrade produced corrupted NVRAM.



You will always find message board threads by those who have disobeyed the upgrade instructions without dire consequences. These people can also eat pizza for three meals daily and never gain weight, and smoke a pack a day until they’re 98 years old. In fact, they often smoke and eat pizza while upgrading their routers. But the rest of us – we're not like them. Just follow the instructions, carefully.

                  Page 1   Page2    Page 3

Continued Troubleshooting a Linksys Router

Check that the router can see your computer by checking on the Device List. If your machine is there, the connection is intact. Ensure that the wireless connection is enabled on the client machine and that any firewall is allowing the connection through. On a Windows machine, go to Control Panel, Network and Internet, Change Adapter Settings, right click, select Properties, Configure then scroll to the Channel setting.
Ensure the wireless channel on the client machine matches the one configured on the router. To be extra sure, change them both to something different and save the settings. If this makes no difference, very briefly turn off all security on the wireless connection and try to connect.
If you can connect, reset the security, and the username and/or password. If it makes no difference, switch it back on again. Next check the type of wireless connection you have configured. Making sure whatever settings you have on the router are mirrored on the client PC. Especially things like security settings, channel, security type, connection type, 802.11b and so on.
As long as all the settings mirror each other on the router and client, the connection should work.
As a last resort, at the back of the router is a small hole, which is the reset button. Pushing a pen or pencil into the hole and holding it for a couple of seconds will reset the router to its default settings. This will give you a baseline to work from, but means you will have to configure it again. This can often resolve issues, as all the settings are entered again, and any configuration issues are addressed with the new commands.
If that doesn’t work either, refer to the Linksys site, and go to the Support section. Follow the troubleshooter I linked to above, or find the latest firmware for the router model. If yours is older, update it.