Please help with TCP/IP connectivity issues

dredd2929

Senior member
Jun 4, 2005
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Hey all. I have a PC and two laptops (call them A and B) that I'm trying to network. A and B will connect to each other (I can map network drives to shared folders between the two), but my PC is not recognized by either A or B. I have a printer attached to my PC that I want to share on the network so this is frustrating. I can pull up shared folders on A and B with my PC but not vice versa.

Also, I was playing around with some stuff and I noticed that in Local Security Settings>Local Policies>User Rights Assignment>Access this computer from the network, there is a strange entry (looks like *S-1-5-21-484763869....). Is this something I should worry about? Can this be removed without screwing things up?

Also I looked at what ports were listening and it looks like 445 (file and print sharing) is listening. Also 137-139 are used by Windows for networking but only 139 is listening. Could this have something to do with not being able to connect? How do I open others if it becomes necessary?
 

TheFamilyMan

Golden Member
Mar 18, 2003
1,198
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Go into Windows Firewall (on the machine not recognized by A & B) and check to make sure that "File and Printer Sharing" are enabled in the firewall. Had a friend that had the same exact issues you are having and in under 1 min on the phone he was up and running.
 

Goosemaster

Lifer
Apr 10, 2001
48,777
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Originally posted by: dredd2929
I'm using Windows XP Pro.

Make sure 'simple file sharing' is checked under tools>folder options > view in my computer or any other system window.
 

dredd2929

Senior member
Jun 4, 2005
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Windows Firewall is turned off. I'm using Zonelarm. My problem persists even with Zonealarm disabled.

"Use simple file sharing" was already checked.
 

dredd2929

Senior member
Jun 4, 2005
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Also, I have already enabled NetBIOS over TCP/IP, but to no avail. One thing I've yet to try is to remove my network adapter from the device manager and then have it reinstalled. But if my internet works, how can my network connection be the problem?
 

dredd2929

Senior member
Jun 4, 2005
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I tried uninstalling and reinstalling my network adaptor, but I'm still having the same issue. It's almost like a port I need opened is being blocked; what ports should be open for file and pring sharing to work?
 

dredd2929

Senior member
Jun 4, 2005
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Well I had a networking expert come by and look at it and he tried everything he knew how to do, but to no avail. He suggested reinstalling Windows XP Pro, which is an option but I really don't want to have to do that. I think I know what is causing it but I don't know how to fix it. I installed a program called System Mechanic by iolo, and ever since I haven't been able to share my folders or printers on the network. We uninstalled the program but that didn't help. I'm thinking that that program modified a .dll to cause it to stop working.

Any suggestions on how to check to see what .dll files have been modified or added, or how to restore them to their state before installing System Mechanic? I tried System Restore but it failed...probably not a good sign.
 

techjunkie2007

Junior Member
Feb 2, 2007
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Make sure the local security policy is the same on both computer. NTLMv2 settings might be different. Good luck.
 

dredd2929

Senior member
Jun 4, 2005
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I went to secpol.msc on both computers and some of the setting were different. I changed those on my PC to match that of laptop A, and it still didn't fix the problem. Are these the settings that you were referring to? What is NTLMv2? Is this one of the listings in the Local Policies window, or is it a specific file that I need to edit?
 

dredd2929

Senior member
Jun 4, 2005
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techjunkie2007: OK, I see what you mean. I have all my computers set to "Send LM and NTLM responses". This provides the highly level of compatibility, am I correct?
 

techjunkie2007

Junior Member
Feb 2, 2007
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I'm no expert but making sure both computer have the SAME setting was what made it work for me (NTLMv2 were enabled if I recall correctly). Before, even though I have shared folders enabled on one computer on a LAN, when I try to map to that folder on another computer as a network drive, the account/psswd authentication would always fail and the account would get locked out. Hope this helps. Good luck.
 

dredd2929

Senior member
Jun 4, 2005
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I ended up figuring it out.

I went to my LAN connection properties > TCP/IP properties > Advanced > Options (tab) > TCP/IP filtering properties

I had "Permit Only" selected for TCP, UDP, and IP Protocols, but no ports were specified!! I changed them all to "Permit All" and everything started working like a charm.

Thanks to all for trying to help.