Internet speeds dropping to near zero at random
This has been going on for many months now and I've tried everything I can think of and searched around for a similar problem, but I still can't solve this one. The symptom is that at random intervals ranging from 2 minutes to days or even weeks sometimes, the speed I can get on my internet connection becomes basically zero. Not absolute zero, as a few bytes get in and out, and if I wait long enough (2-30 minutes say) I can actually load a web page, let alone actually download anything. So the connection is still there, just not useful at all. In order to get it behaving normally, I have to reset the connection somehow, such as rebooting, or more recently I have discovered Wicd, which allows me to do it much more quickly. Still, while sometimes I can go a week or more without seeing the problem once, often times it will happen every 2-5 minutes while I'm trying to download something which means I have to keep an eye on it and reset the connection regularly, otherwise it won't download.
For specifics it seems to happen most often (but not always) when I am downloading a large amount of data, like a torrent file. I've used two different programs (KTorrent and Vuze) and they both have the same problem. But I have noticed it when downloading just with a web browser, or even just after I've been away from the computer for a while, like overnight. It's not the cable modem/router or ISP, because I've switched ISPs lately. It's not the hardware because I've tried to replicate the problem in my windows (7) partition on the same computer, but it has never shown up. There are also two other computers on my home network and they never have the problem (both run windows). So if it's not hardware, application, or ISP related, that leaves the OS, as far as I can tell. But when I upgraded my system from 10.10 to 11.04, nothing changed, I still have the same problem. The only other thing I can think of to try at this point is a complete wipe out and reinstall of the OS, but I'm hoping for an easier and more specific solution, if anyone can help.
I did see one suggestion online that mentioned IPv6 problems causing timeouts or something, but I don't know how to check that kind of stuff. I did a dmesg, and it mentions "no IPv6 routers present". Could that have something to do with it?
For specifics it seems to happen most often (but not always) when I am downloading a large amount of data, like a torrent file. I've used two different programs (KTorrent and Vuze) and they both have the same problem. But I have noticed it when downloading just with a web browser, or even just after I've been away from the computer for a while, like overnight. It's not the cable modem/router or ISP, because I've switched ISPs lately. It's not the hardware because I've tried to replicate the problem in my windows (7) partition on the same computer, but it has never shown up. There are also two other computers on my home network and they never have the problem (both run windows). So if it's not hardware, application, or ISP related, that leaves the OS, as far as I can tell. But when I upgraded my system from 10.10 to 11.04, nothing changed, I still have the same problem. The only other thing I can think of to try at this point is a complete wipe out and reinstall of the OS, but I'm hoping for an easier and more specific solution, if anyone can help.
I did see one suggestion online that mentioned IPv6 problems causing timeouts or something, but I don't know how to check that kind of stuff. I did a dmesg, and it mentions "no IPv6 routers present". Could that have something to do with it?