Question

Something blocking port 80 / Can't access websites

Asked by: Malevolo

I have a laptop running Windows XP SP2 in a network environment that is not blocking or filtering any content over port 80.  For some reason, I can not get any data/access over port 80 through that laptop: I can't go any standard websites and I can't telnet to anything over port 80 (telnet google.com 80). All other ports, including that for SSL work perfectly fine, so I can access any secure websites running via port 443. I've run tcpview and some other applications to see if any application was running on port 80 and nothing is there. When I try opening internet explorer I can see IE trying to access the website's respective IP addresses over port 80 but nothing happens and eventually the load dies saying the page could not be found.

See below for notes/things I've tried doing.  Any suggestions as to how I could try and proceed in troubleshooting this issue would be greatly appreciated

Notes:

1) Everything works fine when loading under Safe Mode
2) I've tried a selective startup with everthing disabled --- this did not help/work
3) Internet Explorer/Firefox are configured for auto-proxy (aka No Proxy Server)
4) Norton Internet Security is installed, and has been for over a year now. I've tried disabling this completed.
5) Cisco's VPN client may have been installed and then uninstalled around the time this problem occurred; I'm unsure. The application is no longer installed.
6) It appears that only port 80 is being restricted as DNS/SSL/ICMP protocols function perfectly.

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Asked On
2008-05-05 at 05:38:30ID23376209
Tags

firewall

,

port 80

,

can't access websites

Topics

TCP/IP

,

Network Software Firewalls

,

Windows XP Operating System

Participating Experts
7
Points
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Comments
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Answers

 

by: flubbsterPosted on 2008-05-05 at 05:45:13ID: 21499580

Could be due to a corrupted TCP/IP stack or bad LSP.

Try this:

http://www.xp-smoker.com/downloads/xptcprep.exe

 

by: DelphineousPosted on 2008-05-05 at 05:52:02ID: 21499615

This could be caused by malicious software or a damaged stack (as flubbster said).

Try running from a command prompt
NETSH WINSOCK RESET
Then reboot.

If that doesn't work, run ComboFix - Download ComboFix (http://download.bleepingcomputer.com/sUBs/ComboFix.exe) and save on your hard drive.

I found booting into Windows Safe Mode (F8 on startup - before you see the Windows startup screen) ensures limited interference from malicious software and any installed security software.


Run ComboFix and let it finish - do not click outside the window or run any software.  ComboFix will restart windows as part of its process then run "Find 3m".  Once complete it will display a log in notepad showing what it found and removed, as well as some other information.  You are welcome to post the log file as a "Code Snippet" for further analysis by an Expert here.

 

by: FOTCPosted on 2008-05-05 at 06:14:33ID: 21499741

i would be you $5 its a problem with nortons. uninstall it...not the normal way either.  it gets corrupt for whatever reason. but download the appropriate tool and run it...

http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039

restart the pc and try your internet again. even though you disable nortons it's still active and will still keep the port messed up.

but, run that uninstaller tool and i bet ur internet will work again....

 

by: FOTCPosted on 2008-05-05 at 06:15:15ID: 21499748

if it works...reinstall nortons or get a better firewall/AV solution. =)

 

by: TriviousPosted on 2008-05-05 at 06:45:04ID: 21499951

Other than the offered solutions I would just make sure that your firewalls are off (including windows if applicable).

 

by: MalevoloPosted on 2008-05-05 at 07:59:17ID: 21500501

Update:

Tried reinstalling TCP/IP Stack/WinSock but it did not help.
Tried running Combo Fix (in Safe Mode and regular...) and that did not help. (Log file is attached)

Currently running Norton Removal Tool to completely remove norton application(s) and will advise to see if that helped.

 

by: MalevoloPosted on 2008-05-05 at 09:02:46ID: 21500946

Removing Symantec did not help either...

 

by: DelphineousPosted on 2008-05-05 at 09:35:56ID: 21501170

I know you have worked with rebuilding the IP Stack, but have you installed the latest network (NIC) drivers on the machine yet?

Do you off-hand know what changes (if any) were made to the machine the day it last worked?

You stated the browsers are configured for auto-proxy.  Do you require a proxy server to access the internet?  If so, how is the Proxy policy applied to the machine?

 

by: TriviousPosted on 2008-05-05 at 09:38:12ID: 21501188

It would be a wise investment to check your logs as well, if you haven't already. This may very well tell you something you don't see. Something below the surface and less obvious could be your culprit. Just trying to think outside the box a little. Sorry that I cannot help more in this scenario.

 

by: FOTCPosted on 2008-05-05 at 09:53:49ID: 21501311

ok so no go on the nortons....

guess i owe u $5 =)

every time i've seen these types of issues, it's always been a firewall/AV issue...not saying for sure that it is the case though...

are there any other firewall types installed? zone alarm or anything like that?
do you have the windows firewall service disabled?

Start > Run > "services.msc (without quotes)

find the "Windows Firewall/Internet Connection Sharing (ICS) service and make sure it is stopped. Set it to disable.

 

by: sfranksPosted on 2008-07-24 at 16:14:42ID: 22084558

I had almost the exact same issue. Unfortunately none of the above suggested solutions resolved it. I was able to find instructions on a blog and following them solved my problem. I thought I would share them, they come from a blog by Ralph Whitbeck (http://www.damnralph.com/CommentView,guid,4ab62f8b-c0bc-4b3e-a965-3033d0d5e018.aspx)

Topic: Uninstalling Cisco VPN client kills internet access

Symptoms

On starting the computer the computers internet access will work normally for a short period of time. Then access to normal websites will be down. Access to https sites, internet application such as instant messaging and e-mail are still accessible.

Cause

Uninstalling Cisco VPN 4.0 client doesn't fully uninstall hidden Zone Alarm Firewall which causes a block in port 80 on the computer.

Resolution

Cisco VPN client version 4.0 includes firewall functionality from Zone Labs Inc. It is possible that a failed Zone Labs uninstall left an incorrect value in the systems registry and must be changed. To resolve the problem follow these steps.

Caution This procedure contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs.

Step 1 Restart the computer and when your computer screen displays the startup message like "Starting Windows..." and a progress bar at the bottom of the screen, press the F8 key on the keyboard. This should display an advanced options screen.

Step 2 At the advanced options screen select "Safe Mode" as a startup method.

Step 3 If prompted, login to the PC once it is booted (you must have Administrator rights to login in Safe Mode).

Step 4 Click Start > Run and type "regedit" in the Open: box (without the quotes) and click OK. This launches the Windows registry editor.

Step 5 In the registry editor, browse to the following path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\vsdatant and select the Start parameter in the right pane.

Step 6 Right-click Start and select Modify. In the Value data: field enter the number 3.

Step 7 Click OK and exit the registry editor.

Step 8 Restart the computer and boot normally; the problem should be resolved.

 

by: heusunPosted on 2008-12-12 at 17:59:40ID: 23162577

I encounter the same problem as above and finally make it work...but don't the reason yet....
It happen twice:
1> after upgrade new vpnclient..., So  Only I use vpn client to login in and exit, then my browse works. (later it auto recovers...without this step...)
2> after I remove cisco vpnclient. The browser didn't work.
So I
.step 1: Reinstall vpnclient
STEP 2:you have to configure this vpnclient well to access the target site you have done .

Anyway, above it is just a little personal experience after painful trip....hope a little hints for you....

 

by: heusunPosted on 2008-12-12 at 18:00:08ID: 23162578

I encounter the same problem as above and finally make it work...but don't the reason yet....
It happen twice:
1> after upgrade new vpnclient..., So  Only I use vpn client to login in and exit, then my browse works. (later it auto recovers...without this step...)
2> after I remove cisco vpnclient. The browser didn't work.
So I
.step 1: Reinstall vpnclient
STEP 2:you have to configure this vpnclient well to access the target site you have done .

Anyway, above it is just a little personal experience after painful trip....hope a little hints for you....

 

by: heusunPosted on 2008-12-12 at 18:07:55ID: 23162603

I think answer from

sfranks

It is a wonderful answer

 

by: tjmacksterPosted on 2010-02-08 at 10:12:23ID: 26516258

Thank you sfranks!  I have been trying forever to figure out how to fix this and your steps worked exactly as stated:

"Topic: Uninstalling Cisco VPN client kills internet access

Symptoms

On starting the computer the computers internet access will work normally for a short period of time. Then access to normal websites will be down. Access to https sites, internet application such as instant messaging and e-mail are still accessible.

Cause

Uninstalling Cisco VPN 4.0 client doesn't fully uninstall hidden Zone Alarm Firewall which causes a block in port 80 on the computer.

Resolution

Cisco VPN client version 4.0 includes firewall functionality from Zone Labs Inc. It is possible that a failed Zone Labs uninstall left an incorrect value in the systems registry and must be changed. To resolve the problem follow these steps.

Caution This procedure contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs.

Step 1 Restart the computer and when your computer screen displays the startup message like "Starting Windows..." and a progress bar at the bottom of the screen, press the F8 key on the keyboard. This should display an advanced options screen.

Step 2 At the advanced options screen select "Safe Mode" as a startup method.

Step 3 If prompted, login to the PC once it is booted (you must have Administrator rights to login in Safe Mode).

Step 4 Click Start > Run and type "regedit" in the Open: box (without the quotes) and click OK. This launches the Windows registry editor.

Step 5 In the registry editor, browse to the following path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\vsdatant and select the Start parameter in the right pane.

Step 6 Right-click Start and select Modify. In the Value data: field enter the number 3.

Step 7 Click OK and exit the registry editor.

Step 8 Restart the computer and boot normally; the problem should be resolved. "

Thanks again!

20120131-EE-VQP-002

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