What Causes A Router To Fail?

In the context of this article I’m referring to consumer grade home internet routers, as in the type that typically have one WAN or "Internet" port and four LAN ports.

It’s quite difficult to pin down what specifically causes a router to fail. For example, if you have a dead router, hand it to an electrical engineer and asked him or her…

"Can you tell me what caused this thing to die on me?"

…the engineer would not say, "It was x that killed it."

Instead, testing would have to be done to determine the cause, and it would take a while. Maybe it was crappy firmware. Or an electrical short. Or it suffered from some heavy EMI. Or it was tiny bits of condensation. Or it was something as simple as a bad power adapter. Or something else entirely. There are any number of ways to kill a router.

It’s more important to rule out false positives and know how to recognize warning signs, if any, that a router is about to fail.

Ruling out false positives

False positive for a router failure: Google Maps

I know of one real-world example that can be replicated easily, making it appear like your router is having a problem when it in fact isn’t.

Using the web site Google Maps on the Windows operating system with any web browser, if you load up a map then quickly pan the map in combination with some fast zoom in/outs, this will make too many network requests and cause your internet connection to "freeze" for up to 90 seconds.

Google Maps works in such a way where it contacts several different servers at once when panning/zooming around the map, and using it too quickly will time out the connection temporarily in Windows.

You may say, "But my router can handle a ton of connections. What gives?"

Since Windows XP Service Pack 2 up to present with Vista and Windows 7, the Windows OS is purposely engineered to limit network requests whereas previously it wasn’t.

End result: Not a router problem. It’s Windows doing it – by design.

I have only been able to replicate this issue using the Google Maps web site. Google Earth doesn’t have this problem and neither does Yahoo! Maps, Windows Live Maps, MapQuest or any other mapping site. Or any other web site for that matter.

To rule out my own router as the problem, I tested this on another ISP using a router made by another manufacturer. Same result. Time-outs with Google Maps – but only on Google Maps when using it heavily as noted above.

False positive for a router failure: Bad network cable

A new router obviously won’t cure a bad network cable. If troubleshooting a router, always replace the network cable first, both to the PC and to the cablemodem.

Ruling out a bad port

It is not outside the realm of possibility that the port on the router that connects the network cable to your PC’s network card is bad. If you’re plugged into port 1, try port 4.

Why 4 and not 2?

Because it’s the furthest away from the port which may be causing the problem.

To note: Having a bad port is an unlikely situation, but as said above it’s not outside the realm of possibility.

Are there warning signs when your router will fail?

In most instances there are no warning signs when a router is about to stop working. You’ll be using the internet normally and then *poof*, dead connection. Modem lights look fine but router lights are either all on, all off or blinking in a "weird" way.

More expensive routers will give at least a little bit of warning (usually 4 to 7 days) before failing altogether, seen in the form of random disconnects. One reason this this may occur is because the crash recovery isn’t working properly any longer, causing the connection(s) to drop at random intervals. And that’s all the warning you need to know that yes, the router will stop working soon.

What can you do to extend router life?

It’s easy to extend the life of your router if you follow these simple steps:

1. Keep it off the floor

Some people simply run out of desk space and "demote" the router to the floor. Bad idea, because that’s where all the dirt is. And even though your router most likely has no fans, that doesn’t mean dirt cannot get into it and end the router’s life early.

2. Avoid cable stress

Network cables that are pulling on their ports is just bad news. If you’ve got a network cable that’s just slightly too short and has tension on the port it’s connected to, do yourself a favor and just buy a longer network cable.

3. Keep it away from the PC

Common occurrence: Seeing a router sitting directly on top of the PC. It shouldn’t be there. The PC is vibrating, even if only slightly. Those vibrations can lead to early router failure later.

Not all PC cases vibrate, but many do – especially when the optical drive is in use.

4. Never shut it off unless you absolutely have to.

I have heard the story more than once where someone shuts a router off, turns it back on, and it dies.

Unless troubleshooting a network connection, there’s really no reason to ever shut a router off.

5. Don’t upgrade the firmware unless it’s required.

Router firmware updates are like BIOS updates in the respect that you should never apply the upgrade unless there’s something specific in it that fixes a legitimate problem. If there is no problem to be fixed, don’t do it.

Read the release notes for router firmware updates first and always.

If from the release notes you learn the update patches a security hole or two, then yes, you should apply it immediately.

If on the other hand you discover the update doesn’t fix any security holes (which most likely means that none exist), add any features you need or the like, don’t do it.

Have you ever had a router die on you? If so, were you given any warning?

Post a comment or two and let us know. Remember to list your router make and model.