Interesting Network Problems With An Unusual Solution

I spent some time this week helping a fried with his new iMac computer. Actually, he bought the gorgeous thing for his wife. Unfortunately, he couldn’t get it to connect to the Internet reliably — even with the help of friends, Apple tech support, and even returning the computer for a new one.

When I first heard about the problem, I understood that it would not connect at all. I suspected that the router was locked down such that it only would talk to specific MAC addresses.

That turned out not to be the case.

The first step was to sit at the iMac and make a note of its MAC address. I found that via Finder > Applications > Utilities > Terminal. I typed
   ipconfig
and pressed the Enter key. The response listed all the interfaces, and told me the the Ethernet Interface EN0′s MAC address. It also told me that EN0 had IP address 192.168.0.198 assigned to it.

Hummmmm, I said. That means the router as talked with the iMac and has given it an address (the hardware has a default 167.x.y.z address that is assigned if nothing else assigns an IP address to the interface). That means the problem is somewhere else.

Since the Ethernet connection from the iMac goes straight to the router, there wasn’t anything else in place to filter or mess up the connection. That meant the problem was still something in the router.

I went to the router, logged into its administration screen and started reviewing the settings.

Nothing stood out as an obvious culprit. I went back to the beginning and started looking at the non-obvious things. Still nothing.

Then, I saw the first hint of something wrong. This was one of the newer Gigabit routers with wireless, but the firmware was dated in July, 2007!

I went to the Belkin web site and checked for newer firmware. Sure enough, while he had version 1.11, the latest was version 1.21, implying that there had been 10 interim updates. I downloaded the firmware update to his computer.

Then, from the Belkin router’s administrator panel (via a web browser), I made selected the option to update the firmware and pointed the program to the newly downloaded file.

The firmware update was a well-written piece of software. It asked to confirm that I wanted to update the router’s firmware. When I confirmed that,it began — and gave me a countdown to the estimated finishing time (about 80 seconds) and a warning that, if I hit the back button on the web browser, I would damage the router.

Great warning. I would have said "Don’t do anything else when you’re updating firmware — keep your hands off the keyboard and mouse until the update is finished!"

Anyway, the firmware update solved the problem. The wife was happy. The husband was out of the doghouse for a bit.

The answer wasn’t obvious, but it was there. All signs pointed to the router, and that was the only thing left to do.

While I was at it, we set the Admin password on his router. There is malware alive on the Internet that looks for home routers that do not have a password, or have a simple password, so they can set up "man-in-the-middle" attacks. See my article Malware Silently Alters Router Settings – Change Your Router Passwords!.