There are so many things that could be causing this it's hard to suggest anything other than to check everything one piece at a time. First, you should probably check with your ISP or on forums related to your ISP. Maybe other people are having the same problem and it's the ISP's fault?
Also, don't rule out your hardware just yet--I made that mistake recently. I've had the same external broadband modem and router for about 4 years now, and a few months ago I couldn't connect anymore. All the modem diagnostics were telling me that the ISP simply wasn't responding. I swapped all my cables one at a time (thus ruling out cables), plugged directly into the modem (thus ruling the router out), tried different computers (thus ruling out the computer and software), connected the modem elsewhere in the house (thus ruling out home wiring), then I called the ISP and argued with them for a while. Eventually, I think re-flashing the firmware in my modem a few times (it didn't work the first time!) fixed the problem. Doh. I use the factory defaults for my modem so it wasn't something I did--the modem was just losing its mind.
Anyways, that's the kind of step-by-step approach it takes to figure out connection problems. What makes it worse in your case is that it's intermittent. Can you get it to happen reliably by, for example, maxing out your up or downstream bandwidth? If you can find the circumstances that cause the disconnection it would make finding the cause easier.
Bravo, Tigerm... nice write-up!
Really not much to add. If you have a router that gives you an IP address, you might try
from the command prompt. But, this will accomplish basicly the same thing as if you unplug the cable for a few minutes.
Also, if you don't think it's your problem, don't forget to call your ISP and bitch! ^^
thanks to Silverwmoon!
Yeah, I experienced the same problem not too long ago,the city where I live, part of it experienced a temp blackout, my apt has its own power generator, so I didn't notice the blackout, and my local ISP is affected by this blackout.
I dunno if anybody else has this but..my router is fine ($175 piece) and it's great but my modem is very old external model, and it's prone to "overheating"?
Since I leave my computer on all day (I haven't shut off my comp since last week) downloading anime and stuff, one day I experienced a series of disconnects. I checked everything and it was all good, and when I put my hand over the modem to check the cable the modem was burning hot!
So just in case that happens..turn off your computer once in a while T_T