Linksys WRT54GS not connecting via LAN to Internet

Ran across this issue at TechLab 2000, a friends shop in Baltimore. After doing some exhaustive physical troubleshooting (checking the 16 port hub back end, looking for incorrectly wired cables, checking the Windows and McAfee firewall settings), I figured my best shot was to do more Internet research.

This made absolutely no sense why the configuration would work for months, and then over the span of a week, peter out on him. Wireless connection worked to the Internet, and the LAN connected PCs could get to network shares, but not Internet. As a 'quick' fix for the day, I stuck Wireless G PCI card in the PC he used for processing online orders, and left a little frustrated after @ 4 hours of work.

Later on that evening, I did some investigating and stumbled across this forum noting an almost identical problem. The Wireless and LAN connections worked fine for quite sometime, and then magically, just stopped working. I emailed the store owner and mentioned that this maybe the cause of the issue, even though the case history of his particular issue was pointing me at a 'new' setting that would have changed his infrastructure (i.e. Firewall exception or a Microsoft Update). I asked if he could email me the Version # on his router and login to the router web GUI and give me his current Firmware version (things I should have done the previous day, but did not). I sent him the link from Linksys' site detailing how to get all this information. Let's just say this was a bad move on my part.

He promptly returned with a response and I started to mitigate how this problem would be resolved. Keep in mind, the band aid of the Wireless card was working, so the shop was functional at this point.

Here is my first email:

You probably have Version 5 router, since it goes 1.50.6. The latest firmware for that one is 1.52.5, which resolves a host of issues. It is possible that things were working fine and then it crapped out. Linksys offers free technical support, so if you don’t want to wait for me, you can call them and have them walk you through upgrading the firmware. I would do it after hours and you would want to backup your current configuration. It could take a couple of hours to get everything back to normal. I have done firmware upgrades before, and they never seem to get things back to normal quickly.

Here is an email back from the owner:

It's version 6 and i downloaded 1.52.5 firmware, but how do i install it? And do you think the wireless is preventing the wired router from working?

And here is my immediate response to his question about how to install it:

That is possible as well. You could try reversing it – going to the wired router first with the DSL line and then sending a cable over to the Wireless router.

Installing the firmware is kind of tricky. There are instructions on their website on how to do it, but you want to make sure you back it up properly in case you have to go back to your previous configuration.

I then get a call from him an hour later stating that the configuration won't load and everything is down now (mind you, this is during business hours). Unfortunately, I was still working another job and on my way to a viewing, so it was impossible for me to do any phone support or on hand support for the issue. I was worried about his business suffering, but at the same token, I had warned repeatedly to wait to do this move, as it could backfire or may not fix the problem to begin with. Luckily, I received an email the following morning:

The wireless is all taken care of - the firmware's upgraded and all that. Everything's set up. Magically everything seems to be working now. As of this morning.

First Lesson Learned: when in doubt, check for firmware upgrades for Linksys routers, and even if the configuration hasn't changed, it could magically stop working the way it used to.

Second Lesson Learned: Tricky does not equal STOP, NO, and DON'T, which is obviously what I should have said.