Intermittant DNS Problems

As a first wack at the problem, see: faq779-4625

This is not an SP2 issue, but likely malware. See also faq608-4650 as a the very first step.

If I visited your site, I would download, install, update and run a scan with GIANT Antispyware:
(Which Microsoft announced today it has purchased).

Just an FYI, Giant's site was down yesterday, is up today, but doesnt offer download links. I had to get my copy by finding "mirror" sites elsewhere....

Thanks.

rowdy1025,

I had uninstalled SP2 for the same reason and had the same problem ( except that ipconfig release & renew would temporarily work for me ).

I have found a work around for you to try... At the prompt type: ipconfig /flushdns

You may have to do it a few times, or at least every time the problem resurfaces. This works well on my machine and made it usable again. It's been resolving DNS for a few hours now.

good luck!

I've have similar problems on my PC after a fresh build. If I tried to connect to my mail server or web sites all I would get were server not found errors. If I pinged the default gateway or DNS addresses replies were instant. If I pinged the mail server name (mail.adelphia.net) I'd get a bad address message. If I pinged the server name with the "-a" option the address would resolve and replies would be fast and reliable. At this point I could finally connect to the mail server.
At first I thought it was a conflict between the MS Firewall (MSF) and Norton Internet Security 2005 (NIS). I rebooted, disabled MSF, tried to connect to the mail server - with no luck, ran the ping tests and still had the problem until pinging with the "-a" option.
I then rebooted, verified MSF was still off, disabled NIS tried to connect to the mail server - with no luck, ran the ping tests and still had the problem until pinging with the "-a" option.
For whatever reason adding "-a" to the ping command line seems to be the magic bullet - until you log off or restart the PC. This behavior is the same with web browsing. I'll have to try some of the suggested fixes.

Try After much searching and tinkering I have managed to locate someoneon the net who had described almost all simialr symptoms, caused by a varietry of things ranging from spyware to corrupted reg entries etc, in most cases it is a messed up host file and may be fixed by using WinsockXPFix.exe
obtainable at

Hello everyone,

Thanks for the help. I have found and tried all of the solutions submitted here before, to limited success. Actually, two things I have found that, although not solving the root problem, fix the symptoms:

1. install my own dns, such as treewalker. this works best, and allows me to move between networks without reconfiguration, but takes up a lot of cpu and slows the computer down noticably.
2. i found out that, while ipconfig /release&renew and ipconfig /flushdns did not work for me, if i changed the dns settings from obtain automatically to a preset dns address, dns would work for another 30 minutes or so and then stop working again. so, for a while i would just reconfigure my dns settins ever 30 minutes or so. not fun. then, i realized, if i put my wireless router as a dns server, and the dns server from my isp as a backup, i didn't have to keep reconfiguring every 30 minutes. so, this is what i'm doing now. i still have to reconfigure whenever i move my laptop to a new network.

As another note, I completely reinstalled my laptop, upgrading from XP Home to XP Pro. In the process, I foolishly installed SP2 thinking maybe the problem wouldn't occur with XP Pro. I was wrong. I'm having the same problem. At least this ruled out spyware though, unless the windowsupate site is now handing out spyware too, as this was the only site visited before the problem reoccurred.

Thanks everyone for the help. If anyone has any other solutions, I will be happy to test them. . .

Check your MTU values.
If using ADSL PPoE, the default MTU of 1500 for your client would exactly duplicate your results, particularly with the mail client.

To resolve:

. Test

. Adjust both router and client MTU values based on the tests. The router MTU can be done through the router web-based setup page. The XP client MTU through a utility, such as DrTCP:

You have every indication of a invalid MTU setting. See the following discussions:

Hello bcastner,

Thank you for your response. I'm sorry though, but it was a bit over my head. I have a cable connection without PPoE (there's no authentication). I checked the tweaks site, and it said my MTU settings were 1500, I think:

Max packet sent (MTU): 1500
Max packet recd (MTU): 1500

I ran the drTCP, and see that I can save the MTU settings for my network card. What should I change this to? 576? Shouldn't the operating system do this automatically if necessary? If both the router and the network card use 1500, isn't this correct? I thought they both need to have the same packet size. I have looked everywhere in the router configuration screen, and can't find a way to change this anyway.

Finally, outside of dr. TCP, where are these settings stored? The registry? Just trying to understand.

Thanks again for the help.

Michael

Your are OK then on MTU.

The last thing to check is possible malware.
See faq608-4650

A lot of malware right now dynamicly changes your DNS and other TCP/IP settings.

Thanks again.

I'm ruling out malware. I reinstalled XP Pro this past weekend (i used to have XP Home), and went straight to windows update. I'm pretty sure the problem started again after installing sp2. With my old install, the problem occurred after installing sp2, and it did not go away after uninstalling sp2.

Manually setting two different DNS servers in the IP settings seems to fix the symptoms, but I have to reconfigure whenever I change networks. I guess I'll have to live with it.

Thanks again,

Michael

Use Device Manager and uninstall all network adapters.
Reboot, and allow XP's New Hardware wizard to re-discover them.

Thanks.

I've tried that too.

Michael

If no evidence of Vx2:
Then:

1. Create a slipstream version of XP with Service Pack 2: Thread779-900263

2. Do a repair reinstallation of XP:

Just a point of info....had same exact problem happen without installing SP2 before. Wound up that Norton Internet Security was corrupt, uninstalled it, and all was well after a system repair. Not sure if you have a firewall on it, especially Norton. Just in case here....

Also, do a search on google for WinsockXP fix. Give it a shot. It's been a great lifesaver about 5 times for me after finding some major spyware damage.

Good luck!