What Causes A Router To Fail?

Posted May 13, 2009 6:10 am by with 10 comments

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.

10 responses to What Causes A Router To Fail?

  1. Floyd Bufkin May 13th, 2009 at 8:41 am

    A thunderstorm took out my client’s DSL Modem and router. Good idea to unhook them during a thunderstorm.

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  2. Steve Stone May 13th, 2009 at 8:54 am

    I have an older Netgear DG834G router that runs alot cooler if it is run in a vertical position rather then being laid flat on a shelf. Airflow is just better.

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  3. mail May 13th, 2009 at 11:02 am

    I used aztech DSL600E before and find my internet connection too slow. After I replaced with new D link DSL520T only I find that my ISP is actually suck.

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  4. Ed Fair May 13th, 2009 at 11:20 pm

    Funny that the question should come up now. I’m 3 days into life with a replacement Belkin F5D5230.

    Things started slowing down a couple of weeks ago but we lived with the problem for a while. Things sometimes are a little slow with multiple machines and some on a 10B2 segment feeding through a couple of Artisoft hubs so it wasn’t that obvious. There was also the issue of Panda Internet Security doing its things in the background.

    About a week ago I swapped the speedstream DSL unit out. The existing one was an ebay purchase that was shipped with insufficient packing and the case has a hole and possible internal damage although it has been working for about 2 months. No difference. Starting last Friday I pulled Panda off the main machine which was direct 100 to the router. Still the pits. Ended up putting up another system, direct to a different speedstream using PPOE to see what the AT&T could do. Direct connection gave the full download and upload I’m paying for. Went back direct to the primary speedstream and it was OK. Threw the router back into the mix and was back at about 1/20th the speed using the speakeasy speed test as my gauge.

    Rset the router both possible ways. Reloaded the setups. No differences. Haven’t tried a reload of firmware yet, I have multiple routers I can use if this one gives up.

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  5. bruce December 31st, 2009 at 9:54 am

    I’m on my third Netgear router. They all seem to end their lives about the same way, with a couple of weeks of sevice drops. Usually a reboot fixes it, but eventually the router no longer can feed data through from the modem. Most of the other functions work – the radio works, the operating system is fine, cables ports are good, etc. I go thru all the checks to rule out other equipment and my router sits up on a high shelf in a quiet, fairly clean area in a room that does not get hot or cold. I have gotten about 2 to 3 years out of each of the last two routers. A new one always brings the network back to normal again. So what is it? I’m not sure, but one thing I suspect is the NAND memory, which degrades gradually with use. Since the routers keep logs and other stuff that is constantly changing with use, it occured to me that perhaps the NAND was being degraded over time to the point it would no longer function and then perhaps that was causing the problem. I have no way of knowing for sure, but maybe one of you engineers out there might be able to figure it out. If this is the problem, then the manufacturer is building in a life span based on usage.

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  6. Keef June 22nd, 2010 at 4:19 pm

    I think the reason is simple: they are purposely designed to fail after a year or two — so you'll have to buy another one. I've been through about 5 or 6 now by different manufacturers and the pattern has always been the same.

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  7. Herb May 21st, 2013 at 5:46 pm

    You will never believe this.

    I run a small ISP. Most customers have Linksys/Cisco, Netgear, Apple routers — all types and models. Our system was down for 10 hours. When it came up, I had well over a dozen calls with bad routers. THe routers would get an IP, the clients would get a local IP, but one could not ping from a client to a network. In a few cases I was able to reset the router to factory default, but in most cases the only solution was to replace the unit. I’m thinking that the router spent the 10 hours doing DHCP attempts one after another and that somehow overheated something — that’s the only thing I can come up with.

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  8. dosmastr February 7th, 2014 at 4:03 pm

    I never had one *die* but I’ve had the Ethernet ports on the back slow to a crawl (tried diff pc, tried different cable, tried all 4 ports…. Ethernet was 2-5mbps and the wifi was running at 16 of the rated 25 cable connection)

    it still works but its slow and doubles the ping time from 10 to 20 on Ethernet. Its very curious, I’ve never seen something half fail like this

    Perhaps bruce has the answer

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  9. B Huss February 17th, 2014 at 3:57 pm

    I had a Belkin Router for 3 years, attached to a Wild Blue satellite modem on an Acer PC. The router started slowing and finally stopped working at the end of September. I bought an ASUS RT-N53 router on September 23rd. It died on Dec 23rd. The tech service had me send it in for repair. It cost $11 to pay for shipping with FedEx, which was all they would accept- no they didn’t pay for shipping on a warrantied product. I got it back and installed on Jan 7th. They told me that they would either recondition it or send me a new one. I called and asked which they had sent, but no one could tell me. Well here it is, Feb 17th and it doesn’t work again. There was no warning, last night all was fine, this morning no connection and the 2.4 GHz LED light is flickering. The router and modem are in a clean, dry and cool location. We haven’t had any storms or power surges, and they are attached to a good surge. Knew what to try, went thru that drill less than 2 months ago and their customer service is closed today anyway. Have the modem plugged into the CPU where it works just fine, but no one else can use their networked items again. I am going to run down to the electronics store and buy a new router, some other brand. Just sharing, if you need a router, I’d skip ASUS.

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  10. Shildor April 20th, 2014 at 12:56 pm

    Over the years I have come to the conclusion that Routers are built to fail after a couple of years of use. (Like Keef said). Like to see one offered with a 5 year unconditional Warranty (That will be the day -lol )

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