This has happened to me a couple of time over the last few years, most recently just this morning.
My computer says I have good internet access, and I can access a few big sites (Google, Wikipedia, Netflix, my email server) but all other sites (amazon, bing steam, any number of small sites) time out. Once I reset my modem the problem goes away, hence my ability to start this thread.
Although the problem is clearly fixed I am curious as to what could have technically caused it. I would have thought that the internet acess would be more or less all or nothing. Or at least if there were certain sections that got walled off it would be a problem with my ISP or a global problem, not just a problem with my individual modem.
Does anyone know what could cause a modem to accept traffic from large popular sites but not small ones? If it matters I am on a cable model with comcast as my ISP.
No, wait, that’s what UFOs usually are. It is probably a problem with the Domain Name Server your ISP was using, with major domains cached and smaller ones having to be accessed elsewhere.
I used to have these problems all the time with a particular AT&T modem. I made them swap it out with another model, and I haven’t had any problems since.
I thought it was probably something like that but I thought that all the DNS stuff happened at the ISP or higher level and so I couldn’t figure out how resetting my modem could fix the problem. But it sound like (based on the link you helpfully provided) that designating a DNS server for my computer occurs when my my network is linked to the internet. So presumably it was previously connected to a bad one, but was directed to a better one when I reset.
There could also potentially be a problem with your local DNS cache. Google clear dns cache to find out how to do that with whichever OS you are using.
Another possibility is malware on your router. Some types only persist as long as there isn’t a reboot. Such malware can cause all sorts of weird behavior. (In addition to tracking what sites you visit and scanning the content of unencrypted data. Well, encrypted too if it’s doing a sophisticated man-in-the-middle attack on badly run sites.)
You could check for updated firmware for your router but that’s a long shot all too often.
If you’ve had your router for 3+ years, it might be time to replace it.
I’d love to hear how you fix it, if you do, because I’m having a similar problem…one laptop can’t access certain sites. Other devices going through the same modem can. Also, I can access everything on that laptop if I plug it into the modem via ethernet.
I can’t ping those sites, either, but it does resolve the host name when I try and come back with an IP, which it tries to ping but fails. I’ve tried several different browsers, I’ve scanned for malware, I’ve tried a system restore. No luck.
I’ve tried rebooting the modem, flushing the DNS, pointing to a different DNS server. Everything fails. Once, I de-activated the wireless adapter and re-activated it, and it worked for five minutes.
Even stranger, the same laptop works fine if I put it on a different wi-fi network. So it seems that it’s not just the modem, or just the wireless adapter, but some weird combination of the way the two of them work together. I’m running out of ideas on how to fix this.
I also have had similar problems off and on, and have started thread(s) about the problem. My Wifi provider seemed to blame it on some “signal collision” or such, and indeed the problem hasn’t been seen since I got a new receiver and get my Wifi from a different transmitter (though same provider).
When I had problems, I could get to the otherwise-inaccessible sites using Tor browser.
I would guess your DNS server goes down, and all you have are the big sites where the IPs were already cached. I would thus suggest editing your options to not use your ISP’s DNS server.
What I want to know is why my DSL can connect at full speed, and the Wi-fi upon testing can run at full speed, but the actual download speeds are awful. It’s been happening way too much lately.
I’m talking going from 6Mbps to 0.1Mbps. It’s ridiculous.
Maybe the site you are attempting to download from can’t keep up with the demand or has some other problem? Or maybe your computer can’t keep up the flow of incoming data?
How old is your modem? If you have an older modem running an older firmware, your ISP might just throttle you down until you upgrade. Comcast did that to me.