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February 23, 2005 8:32 AM

On a fairly regular basis, even if I'm in the middle of using it, my cable modem connection vanishes. Fixing it involves unplugging the modem and router, waiting a few minutes, replugging them and crossing my fingers. I gather this phenomenon is extremely common. What can I do to prevent it, and more importantly, why does it happen in the first place?
posted by squidlarkin to computers & internet (16 comments total)

I sometimes have to unplug and replug my netgear router.
posted by drezdn at 8:49 AM on February 23, 2005

My first guess is that there might be a glitch in its firmware. Have you checked the vendor web site for an update?
posted by kimota at 8:52 AM on February 23, 2005

Yes, check the firmware. Check for any updates/patches on your ethernet card, or maybe try reinstalling the drivers entirely. As a last resort, call your provider and ask them for help. It could be a number of things, including stuff out of your control (such as low signal from the repeater, etc.).
posted by nitsuj at 9:09 AM on February 23, 2005

In this small Oregon town, DSL service is provided by the local phone co-op. For some reason, about once per week the local DSL connection goes down. This happens at my office, it happens at the local car company, it happens at the local accountant's office, and it happens in another office I know about. Each of us takes care of this by unplugging both the DSL router and our internal router for a few seconds then plugging them back in.

I don't think anything can be done to prevent it.

Why does it happen?

I don't know, but I suspect that it's related to DHCP. I'm willing to wager that these dropped connections are occurring when the DSL modems are sending out requests to renew IP addresses. Does that makes sense?

Again, that's just a guess...
posted by jdroth at 9:10 AM on February 23, 2005

I had a similar problem when I had cable in an older house. The cable company had just hooked us into the existing wiring, and I would lose the connection a few times a week. Then they finally came out, dug a trench, and ran new cable. The problem never happened again.
posted by Coffeemate at 9:22 AM on February 23, 2005

I used to have the same problem with my cable modem connection. A while ago, the ISP was finally called and I think they did something to the line that made the problem go away for a while (I know that's not incredibly helpful but I don't remember exactly what this first solution was since it was a while back - just that it was something the ISP had to take care of). After a while, it began happening again, so I called the ISP again, they tried running some diagnostics on the cable modem from theire, and ended up just replacing the cable modem itself. I've not had the problem since so, as big a fan as I am of DIY solutions, perhaps you should give your ISP a call if you haven't already.
posted by DyRE at 9:36 AM on February 23, 2005

I have the same problem when I'm doing torrents sometimes through my (timewarner provided) earthlink cablemodem. CS said that the modems have a bandwidth limiter - you use to much, it shuts you down. I just unplug and go again.
posted by jmgorman at 9:43 AM on February 23, 2005

Mine just started doing this, so I called the ISP. He said that there did seem to be some trouble in the cable - I don't know what he was seeing from his tech support desk, but something - and told me he would send someone over, which is why I'll be home on Friday morning. He said that it can start happening if several people in your neighborhood add cable internet - the signal gets weaker if it's split too many times, or something. At any rate, call them - mine didn't seem surprised at all, so it must be pretty common.
posted by mygothlaundry at 10:17 AM on February 23, 2005

Mine has been rock solid for several years and just in the past week started dropping connections at the modem. Several calls to the cable company produced a few possible sources, all pretty much in the vein of a bad connection. Do you have poor cable reception on the lower channels? This is apparently a sign of a bad cable connection in the frequency range of the cable modem. Check all of your cable connections and re-tighten them. It could also be exacerbated by recent cable additions in your neighborhood in which case the company can amplify the signal to correct this. Mine has corrected itself but I do not know why.
posted by caddis at 10:30 AM on February 23, 2005

perhaps you should give your ISP a call if you haven't already

I have. Several times. They always tell me politely to power-cycle and quit whining.

I have the same problem when I'm doing torrents sometimes through my (timewarner provided) earthlink cablemodem. CS said that the modems have a bandwidth limiter - you use to much, it shuts you down. I just unplug and go again.

I go through timewarner too, but this doesn't make any sense to me. Why include a bandwidth limiter, particularly one so easily circumvented? Simply flipping it off and on doesn't work, either; leaving it off for at least a minute is required for it to "take". Several helpdesk people have even me instructed me to take the (experimentally proven to be unnecessary) step of unplugging the ethernet cables during this process as well, apparently to help the bad vibes dissolve into the aether. Which is why I want a technical answer from someone who actually groks the hardware...
posted by squidlarkin at 11:31 AM on February 23, 2005

Squidlarkin, what's the modem? I used to have the RCA modem that at&t/comcast gave out in Seattle. It was notoriously a piece of junk. Technical answer? I'm not sure I can give you a complete one, but among other things the power connection was grossly unreliable. I replaced it with the newer model that they're giving out & am no longer having problems.
posted by Wood at 12:56 PM on February 23, 2005

The first thing I'd try at this point is replacing the cable between the modem and router. If that doesn't fix it, replace the cable between the router and computer.

I once thought that cables were pretty robust, but I have seen a number of them go bad in the last few years.
posted by Kirth Gerson at 1:18 PM on February 23, 2005

This has only happened a couple of times to me, but I'll bear the cable idea in mind in case it starts happening more regularly.
posted by languagehat at 5:17 PM on February 23, 2005

Check that all of your connections are fine. Try using the modem without the router for a period to make sure it is the modem - it probably is, but then you will know. Call the cable company and have someone come out to check the equipment and signal. If the modem loses the signal, even momentarily, it may very well just get lost until you unplug and then repower it. Find out why it loses the signal. Perhaps force them to swap your modem. Wood is correct about the RCA modems. Comcast sent out new power bricks for these because of all the trouble they were having. If this is the modem you have, get an upgraded power brick, either from your ISP, or from Rat Shack. Good luck. Hopefully some of the suggestions here will let you fix it yourself, but if not make a pest of yourself with your ISP; broadband service costs a pretty penny and you deserve reliability for that price.
posted by caddis at 7:17 PM on February 23, 2005

Third on the RCA modem. Until I replaced the modem, my Adelphia service had to be rejiggered three times a day. With the new one, it goes down maybe once a month.
posted by Wet Spot at 7:57 PM on February 23, 2005

I had similar problems. Called my provider, they came out, deemed my modem "old" (we had it maybe 18 months) and replaced it. Problem solved.
posted by samh23 at 9:38 PM on February 24, 2005