Random, inexplicable network error round 2

[Sovereign]

I am having constant network problems. I’ve tried to iron them out but to no avail. Therefore, I’m basically posting this on every computer/tech site I frequent in the hopes that someone out there can tell me how to fix this extremely perturbing problem.

I have a small network consisting of the following:
- Linksys WRT54G rev. 1 w/DD-WRT firmware preinstalled
- One desktop hardwired into the router (nForce4 A8N32-SLI using the Marvell Adapter)
- Anywhere from one (usually) to three (maximum) laptops connected via Wireless-G
- One university RJ-45 port

Now, other students in other dorms have similar setups and none experience this problem. I can only describe the symptoms as I have no idea what the problem is. It happens to my desktop and laptop, anywhere on the University’s network (in my dorm, in the music building where I work, in the science building, in the library etc).

I’m browsing the internet minding my own business when suddenly I get an “Unable to connect” message from Firefox. There’s no indication that anything has gone “wrong,” indeed I am staring at said message on my desktop while my laptop (connected to the same router) has no problems accessing the internet. These messages are very random, but I usually see it at least twice a day in various places at various times. It doesn’t matter what sites I’m browsing, it can be Digg, Maximum PC, [H]ardForum, LegitReviews, Google News, the Economist, my University’s portal…

The only solution that I’ve found to work 100% of the time is to reboot the computer in question if I absolutely MUST have internet access on that machine. However, this is cumbersome and annoying.

Solutions I’ve Tried (NONE OF THEM WORK, so please for the love of all that’s holy do not suggest “try X again, just to be sure… if “X” is a solution that I’ve listed as NOT working!)
1. Reboot the router (when in dorm room)
2. Wait (usually if I wait at least twenty minutes my internet mysteriously starts working again)
3. Update drivers on the machines in question (no dice)
4. Renew IPs (doesn’t work, regardless of router or not, these “outages” always occur when ipconfig /all shows a valid DHCP lease)
5. Powercycle the offending network adapter by “disabling” it in the Device Manager, and then enabling it again
6. Reinstalling the router (just a pain for no gain)
7. Flush DNS Cache (don’t know what that has to do with anything but I tried it anyway)
8. Log off and log back on
9. Change MAC addresses via a MAC spoofer (MacMakeUp)
10. Router firmware is up-to-date, so it cannot be updated
11. Check Windows Update (nothing found relevant to my problem)
12. Disabling IPv6 entirely (I have Windows Vista on my computers)
13. Terminate and restart Explorer.exe
14. Use built-in Network Diagnostics (they always return a “Windows found a problem that cannot be repaired automatically”)

Just now, my desktop’s internet reinstated itself. What is notable is what happens when I cannot use Firefox (or Internet Explorer for that matter). That is, even though I cannot “access the web,” any downloads (HTTP) or connections to instant messaging services (e.g. AIM, Yahoo!, Google Talk, MSN) that are open before the “outage” occurs remain open and working! Further, I can still ping my router (192.168.1.1) during an “outage.” However, the computer that experiencing the “outage” can see, but not transfer files to or from any other computers on the network, but can be accessed BY other computers, e.g. my desktop has an “outage” and cannot communicate with my laptop. The laptop appears when I click the “Network” option in the Start Menu, but double-clicking results in a network error. I can use my laptop to root around in my desktop’s network shares, but the desktop claims the laptop doesn’t exist even though it shows up on the network map.

Usually, if one machine (desktop or laptop) experiences an “outage,” the other machine can still browse the internet. These “outages” do not seem to be linked between machines.

Does anyone have any idea what the heck is going on? I know that someone is going to post a solution that will have me saying “IT WORKS” and then a week later it’s going to stop working. Please, whoever you are who may post this “one-week” solution, take no offense, it is just that my networking equipment hates me…

[DL126]

Sounds a lot like a corrupted TCP/IP stack.
But I haven't seen that since Windows 98.
And that usually wasn't intermittent. Once it happened, it didn't go "off and on".
A command prompt ping was possible, but the Windows side of networking wouldn't work.

And since it only happens to you, on both your machines ....
Maybe it could be software related. (Some program that you've installed on both machines.)

I assume you're using DHCP, assigned by their server.
Which means that if anyone in an Admin position wanted to "screw" with you, they'd probably be doing it via MAC address.
Not likely, but possible.

Ya know Vista keeps very detailed logs as to what happens when.
If you can remember when this all started, maybe you could check those logs and see if maybe you installed or uninstalled something around that time.