DNS Problem?

[Awol]

Hi all,

i have a dell laptop that the user reported the internet suddenlt stopped sowrking and so did his email etc.

when i got his laptop and plugged it into the network it works fine, but when you connect it using a dial up connection ( bt yahoo ) it doesnt work.

you can ping ip addresses of things like www.bbc.co.uk, but you cant ping the hostnames, you can also put ip address into the address bar and get the page up.

I have never put in dns servers when setting up a dial up connection before, but it sounded like a dns problem to me so i tried forcing dns servers and have tried:

213.120.62.103

213.120.62.104

and

194.73.73.94

194.73.73.95

and

193.113.209.14

193.113.209.46

but none of them seem to cure problem

i tried using the nslookup command, but that says cant find servername for the dns servers, but if i type www.bbc.co.uk etc into that then it does give me the ip address?

i have no idea what else to do/try?

Allan

[scuzzman]

This is surely a DNS problem.

Try this:

Go to start -> Run -> cmd

type in

ipconfig /flushdns

This will flush the DNS resolver cache.

It could also be a problem with the firewall configuration (blocking outbound requests on port 53) so try diasbling that.

One more thing, try calling the ISP for the dialup and getting their proper DNS servers.

What OS is the laptop running?

[Awol]

thanks

i have tried that but didnt seem to help.

when i rang bt yahoo help desk i got an indian woman who i dont think had ever heard of dns, she gave me the dns servers of

194.73.73.94

194.73.73.95

the laptop is also setup on the network and works fine then, out of interest i plugged in network cable, set dns to

193.113.209.14

193.113.209.46

went on 3/4 websites fine, used nslookup and resolved the dns servers rather than saying it coudlnt find them. then unplugged network cable, did a dial up and it seemed to work and nslookup worked aswell.

restarted and it didntwork again? but this time nslookup still resolved the 193.113.209.14 dns server to radius.btconnect.com?

when i first got this laptop to look at it did have quite alot of spyware on it? and the norton on it hadnt been updated in a while, so i updated it, did full scan, deleted some 'at risk' files, not infected ones?

also have booted to command prompt and run sophos with latest ide's did find and remove some infected files.

also run full scans with a program called pestpatrol and spyware doctor which all found and removed some spyware.

and now whichever of these scans i run they all come up clear? lol

[Awol]

oh and its windows 2k professional

[homecomputeraid]

You might try releasing the IP Address on the Ethernet adapter when the dial-up connection is running.

[Awol]

i tried using command ipconfig /release and it said nothgin tied to the adapter or something.

i ran a scan with a program called Stinger and it found a virus called w32/nachi!tftpd in svchost.exe which it deleted but still seems ot have same problem

i have since used the sophos tool for removing w/32nachi virus'

and done the windows updates.

worryingly sophos never found this virus when i was scanning using it? niether did norton? or the trend microsystems scan?

[scuzzman]

You might have a corrupt Winsock2... CLICK HERE for the fix instructions and post back if you require additional assistance with this.

[homecomputeraid]

A Stinger hit also probably indicates that the Antivirus program the person was using was probably not up to date, or was not running. Remember that Stinger only checks for a small number of viruses. If you determine that the Antivirus being used isn't working, download something like AVG which is free, install it, update it, and run a full scan.