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View Full Version : Ping works, DNS doesnt, some users only


DamnMachine
17-06-2004, 04:01
Would very much appreciate any suggestions on where to go next with this problem:

Windows XP machine connected via USB Cable Modem to UK NTL broadband network. NIS 2002 firewall. This is a configuration which worked fine until recently.

However, since installing MS Office 2003, Internet access has stopped working for some users - specifically, those that have used Office.

It's very strange:
- ipconfig /all reports all the usual things fine, including the addresses of two DNS servers that work fine on other machines
- I can ping IP addresses by number, including the DNS servers
- However, any DNS request, such as pinging a domain name, or nslookup reports a failure. nslookup, for example, responds:

*** Cannot find server name for address 194.168.4.100
*** No response from server
*** Cannot find server name for address 194.168.8.100
*** Default servers are not available
Default server unknown
Address 194.168.4.100

If I log out and log in as a different user (one that has not used Office 2003), then everything works fine.

My thinking is:
- since I can ping IP addresses, it's not a hardware problem
- since it works on other users, it must be something specific to some user -- perhaps some Registry key under HKEY_LOCAL_USER?
However, where to start looking?

Any suggestions much appreciated.

Paul
17-06-2004, 10:07
As it's XP - has the built in firewall kicked in for some reason ?

Also check the the service "DNS Client" is running - in fact restart this service anyway - it can sometimes stop working even though it still appears to be running.

Chris W
17-06-2004, 13:47
If you reboot into safe mode with networking and log onto one of the profiles that has problems, does the internet connection work as it should?

DamnMachine
23-06-2004, 16:43
Many thanks for the suggestions on this one. Here's an update.

The DNS service thinks it's running. Stopped it. Re-started it. No difference.

Booting up in safe mode with networking works exactly the same - DNS works on one user, not on any of the others.

Tried creating a new user -- but the new user, as with some of the old ones, can ping numeric IP addresses, but can't successfully do a DNS lookup.
The hosts file and dnscache are empty.

Running nslookup with the debug option on www.ntlworld.com (http://www.ntlworld.com) for example gives the following message:

-----------
socket (dg) failed: No error
*** Unknown can't find www.ntlworld.com (http://www.ntlworld.com): No response from server
-----------

Googling this error message took me to a year old post on www.blu.org (http://www.blu.org), which includes a link to instructions to fix this -- but the link is broken.

This is really puzzling me. There is something different about one user profile which is allowing a basic DNS lookup, where all other user profiles are preventing it.

I can only think of three things which might be different:
1. Some program running somewhere - but I've been through the running processes lists for both users and found no differences
2. The registry - but the only registry entries affecting DNS that I am aware of are the set about the DNSCACHE, and they are the same on both users. And anyway, they are under HKEY_LOCAL_MACHINE not HKEY_CURRENT_USER, so ought not to be different for different users.
3. Could the firewall (NIS 2002) be blocking outgoing port 53 for DNS requests on one user but not the others? And if so, how could I confirm it. Mooching around the NIS 2002 menus I can't see anything recognisable as a simple list of rules about which port to block when.
The suggestion that the WXP internal firewall might be kicked in is also an interesting one, but I'm not sure how to check for this.
All suggestions much appreciated, otherwise a Windows re-install awaits, I fear.

nostra
23-06-2004, 17:37
stupid question but have u disabled norton firewall to see if the connection springs to life?

would be advisable to enable the windows firewall first before you try this...

to enable go to control panel > network connections > local area connection "usb cable modem" > properties > advanced and tick where it talks about firewall..

then try disabling Norton firewall see if it starts working

its worth a try

Chris W
23-06-2004, 17:58
i sure you have tried it already... but try

ipconfig /flushdns

or try refreshing the network shell- at a command prompt type

netsh int ip reset c:/logfile.txt

it should give you no message and just hop back to the command prompt again.

50420
23-06-2004, 21:57
hi damnmachine

this may sound like a strange fix....but i had a very similar problem to the one your having there ...also started after i had installed microsoft office.

office had been installed on the desktop...but not on the laptop which is which has a wireless conection to a belkin router.... after the office install couldnt browse any sites with the desktop but the laptop was fine....

anyways...noticed on the task manager that nisserv.exe was using a considerably large amount of system resources.... checked on symatec site and apparently this was caused by a corrupt urllist file in the NIS folder.

deleted that particular file....ran live update to get a fresh urllist..went ok

and now the desktop is browsing fine !!!!!!!!!

dont understand why this would happen....but thats what fixed it for me..

hope its of some help to you