How about this one?

Briefly, the setup:
I have a small "home theater" HTPC in the living room, and a gaming PC upstairs that I also use for general web browsing. Wireless G router (WEP 128bit) makes the connection between them. Both PC's running XP Pro. Both PC's completely updated via the MS website, and even the router firmware is updated. My cable internet connection comes into the house -> into a Motorola modem -> into the Microsoft branded wireless router -> split into the computers (the HTPC is connected with CAT5, the upstairs runs wirelessly).

The Problem:
The PC upstairs can not sustain a connection to "the internet" - web pages and such I can get online right after the PC is booted up as would be “normal”, but it only last for a few minutes - I haven't figured out exactly how long or what (if any) event leads up to it. Suddenly the the connection breaks and I can't get online again unless I reboot. What's more unusual is that I can get e-mail as long as I wish! Ditto for swapping files and communicating with the other (the HTPC) downstairs. If I get online from the PC downstairs, it also stays connected indefinitely. So the connection to the router stays strong, and I know the cable modem connection stays strong too. But after a couple of minutes from being booted, the specific event of connecting to the internet from the PC upstairs stops.

Any ideas at all?

virus?

I really doubt it. Fresh installation as of this weekend for Windows, and barely had it connected. Norton running, router firewall, etc. Certainly can't be 100% since none of that stuff is bulletproof, but I just doubt that's the issue.

I've found just a tiny bit more. For sure it's http that stops after 5 minutes or so. However, POP3 (email), NNTP (news), and even https (secure web pages) all coninue to work just fine. Something is blocking http after a while.

I don't have Zone-Alarm or any software firewalls installed that I know of. Possibly it's Norton Anti-virus doing something? Or the built-in Windows "ICF" internet connection firewall?

Time for sleep, will continue tomorrow.

Or the built-in Windows "ICF" internet connection firewall?

Do you actually have this turned on? If not, it shouldn't make a difference.

Hmmm...

Assuming you have a broadband link, have you checked your MTU setting? Many broadband carriers (DSL and cable modem) have some limitations here, and you can lose your connection / get "out of sync" easily. You might want to check out this page for information about MTU and other tuning tweaks.

A good way to test the theory is to connect to the internet and only do pings. Use the ping -f command to force non-fragmentation of the packet, and adjust the size of the ping. See if you can find a point that it breaks.

I have this problem with my DSL carrier, and find that I have to force my MTU relatively small. But, having done that, I do not have that problem any more.

My guess is it's because you've got WEP enabled. I've seen this problem before. Disable WEP and you'll be fine. I don't know why this happens exactly and I too was unable to find a solution for it. New drivers/firmware didn't do any good. It didn't even work if the router and the PCMCIA card in my laptop were of the same brand. (and I've tried two brands!)
So I gave up on WEP entirely.

Instead of WEP, I use mac address protection. There should be a setting in your router's menu's where you can enter which mac addresses should get access to your router. Just enter the mac addresses of both your PC's and from then on all other PC's, who's mac address isn't in the list, will be denied access. This works pretty well. It's a bit more maintenance than a WEP setup since you have to enter the mac address manually into the router, but usually a home network stays the same for ages so once the correct addresses have been entered that's all you'll have to do.
Ok, so when a friend comes over and he wants to connect to your network you'll have to enter his PC's mac address to the list too first, but that's it. A one minute process at the most.

Another option is if your router also supports WPA. WPA is a newer encryption protocol than WEP and is more secure. Not all routers support this (yet), but you've got a good chance since it's one of those new 54g routers. Also, windowsXP needs an update before it will support WPA.

Fa small home network I believe tha's a bit overkill though : the mac-address protection is really all the security you need. The range of 802.11x is really way too short to be dangerous. The hacker almost has to be inside your house to do any damage.

First off... Norton IS a virus. I would really recommend removing it and installing something like AVG... but that's just my opinion.

I agree with Archeon about the WEP... just disable that and use MAC address protection. That's what i'm using here (at a college on-campus apartment) and so far have had no problems after 1.5 years.

-Greg

But MAC address protection is trivial to defeat. All of my cards allow you to specifically set a MAC address. You just need to snoop a couple of packets and get a valid MAC address. After that you have free access to your network.

I know WEP isn't exactly brilliant but it's better than nothing. If you have WPA support then use that as it's much more secure. Choose a decent PSK though.

The fact that you CAN connect to the wireless router briefly makes me thing that your settings are just fine - WEP or otherwise.

What are you using on the PC to connect wirelessly? A wireless PCI card? A Wireless USB adaptor? If so, did it come with its own software/drivers to install? If it did than most likely XP's built in wireless networking software is conflicting with your wireless adaptor's software.

What you have to do is open up your wireless network connection properties and uncheck the box that says "Let XP handle my wireless connection" or something to that effect.

I had a very similar sounding problem with a wireless connection on an XP machine just last week that was resolved this way.

- trs

That the POP, NNTP, and especially HTTPS all continue working makes me think that it probably isn't the wireless.

Do you have more than one browser on your computer, and if so does it happen with both? If not, it may be some sort of proxy setting in the browser redirecting port 80 (HTTP) requests to a misbehaving proxy application (though, of course, both browsers might be redirected to the proxy app, so the test only works in one direction).

Before chasing down various wireless problems, do you have a regular ethernet card on the computer? If so, I'd drag the computer downstairs (or borrow a really long network cable), connect it to the wire and see how it behaves. You said that the problem happens within minutes, so you could conclusively show that it is or isn't the wireless layer.

-jk

I had a problem like this, Go to Device Manager -> Properties of the Network card. On the Advanced tap you should see a list of different things. I had to edit some of these items myself to get mine to work. Other cards will have extra taps that you can change things in. Look thru all them on the adapter and change anything specific to your setup: Like SID name, WEP keys, etc…

I also agree with Archeon. Especially if your wireless devices are different brands. I had what sounds to be the exact same problem using an Orinoco silver PCMCIA card with a Linksys WAP11. With WEP enabled the the Orinoco card would spontaniously be unable to connect to anything, connections would just timeout. It was still connected to the WAP with excellent signal strength, but the WAP wasn't forwarding the cards transmissions. I spent quite a while dubbing around with settings and installing the latest drivers. Disabling WEP was the only way I could get it to work. I have since sold the WAP11 and bought an Orinoco WAP and now the system works flawlessly.

Interoperability sucks. (in my opinion)

-Jeff

Have you checked to see if the issue is related to being unable to complete DNS requests? The fact that machines you've already contacted (e.g. email) still work, but new web sites don't, leads me to that possibility.

Try hitting sites (well, those that don't use virtual hosting) directly by IP address when the problem crops up.

-brendan

I'll reply to my own post since there are so many good questions here.

In a nutshell, it WAS &%#@*^@$! ZoneAlarm doing it. I had posted that there were no software firewalls such as that, but - it was installed. See - I recently brought up an old ghost image I had made many months ago, kind of a "known good barebones installation". Well obviously I thought it was good. I think before I ghosted it, I had gone through msconfig and turned a few programs off from the services and startup tabs, including ZoneAlarm. So when I recently reloaded the image, it was never in the systray, and since I hadn't re-installed it since I pulled the ghost image, I had believed that ZA was not installed. Well, hells bells, it had been.

I ran a program on a suggestion from other friends called Ethereal. Basically installed it, opened it up, and had it "capture" activity. Opened a web page, let it hit the DNS error, and then stopped the capturing. Looking at it, one of them identified an IP address 147.208.130.167 buried in it as belonging to the ZA program. Not sure what it was doing, but - it was getting unhappy after a while and cutting me off. Obviously I had not thouroughly kept the program from running when I (thought I had) killed it through msconfig. I did that so long ago I forgot I ever installed it.

So, that's what it was. I reinstalled ZA (I guess I could have uninstalled it instead just as well), and everything is peachy now. Been up for an hour and no problems at all (knocks on wood).

THANK YOU for all the replies and ideas, they were greatly appreciated, and in fact led me down the path of capturing what the network was actually doing. Hopefully it was a fun subject to think about?

Thanks again -

Greg

Please tell me more about AVG! Wazzat?

Free antivirus software with free updates from Grisoft.

Some have said it has missed a couple viruses, but I'll take it over Norton or McAfee ANY day.

*edit*
For me, it's run just beautifully for about a year now. It will catch viruses very quickly (I downloaded a file on a P2P program and the instant I opened the folder it was in (about 5 seconds after it downloaded) the program found it. Plus unlike "Norton the CPU Hog", my machine doesn't appear to take a hit, even though it appears to monitor all the same stuff (email, downloads, etc.).