Aces High Bulletin Board

General Forums => Hardware and Software => Topic started by: Denholm on December 03, 2009, 10:48:31 AM

Title: Networking Issues
Post by: Denholm on December 03, 2009, 10:48:31 AM
Hello everyone,

Just a few months ago we began encountering some networking issues. First it started off with the occasional lockout from network shares, then one of the computers could no longer be found on the network, now none of the network shares can be accessed at any time. I really have no idea how this happened and what caused it. Here's my network configuration:

Internet -> Modem/Firewall -> Computers

Here's the list of networked computers:
Windows XP SP2 Home (x2)
Windows XP SP3 Professional
Linux Mint Gloria

My initial guess is that a service critical to networking was disabled or turned off. However, every service I can think of that has anything to do with local networking is enabled. My next guess was that permissions were changed preventing computers on the network from accessing shares. After using Windows' reset configuration for the registry and files, that theory was smashed. My last (and distant) guess is that some of my security policy settings on Windows XP Professional SP3 were set incorrectly. However, I'm not very certain about this because both our Windows XP Home SP2 computers can't see each other's shares and neither of those two computers have options for changing their security policies.

Before the network went offline, the configuration mentioned above worked flawlessly. I've tried basically everything from re-naming the workgroups to checking our modem's LAN settings and nothing has budged so far. Just to notify those of you who favor the idea of malicious software, I've used NOD32 v4, Spyware Doctor, Malwarebytes, and Spybot to confirm there is no malicious software on the Windows Systems. Any ideas on how to restore our network to the state of, "operational?"
Title: Re: Networking Issues
Post by: BaldEagl on December 03, 2009, 12:22:01 PM
Can you see your shares using Map Network Drives?
Title: Re: Networking Issues
Post by: TilDeath on December 03, 2009, 12:41:49 PM
I would assign each system an IP address (192.168.0.xxx or 192.168.1.xxx), if you happen to have two lan ports on one or all of the system you only need to assign one if you like.  Then in your router configuration first turn off DHCP,  apply the information need for your ISP (gateways etc).  If you have the option within your router to assign a DEVICE NAME and LOCAL DOMAIN NAME do so.  Limit the range of IPs available in your router for the number of systems and devices that need IP address, then make reservations for each system and or device.  Make sure that the systems are all in the same workgroup.  It also helps to have a user name and password common on each system (User name: USER Password: PASSWORD) this makes the shared directories accessible.  As stated above can you see the share if your map directly to the share ( \\MySystem\share1 ).  Just a few thoughts.

TD
Title: Re: Networking Issues
Post by: Denholm on December 03, 2009, 07:03:10 PM
When attempting to use the "Map Network Drive" feature I'm still not able to locate network shares. I haven't tried disabling DHCP, mainly because of the possibility of losing Internet connectivity.

I failed to mention this earlier, I can see networked computers using the, "View Workgroup Computers" feature. However, when I try to open a networked computer other than the one I'm using to perform the operation, I receive the following error.

"\\(computer name) is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions.

Access is denied."

The error is one of my reasons for believing an existing security policy might be causing the trouble. Yet after resetting the permissions I still encounter the same error. :(
Title: Re: Networking Issues
Post by: Auger on December 04, 2009, 12:02:31 AM
Is every PC in the same workgroup?

Do all the PCs have Windows File and Print Sharing enabled in the Network Properties?

Can you ping each PC from each other PC?

Is there a software firewall on any of the PCs?
Title: Re: Networking Issues
Post by: Denholm on December 04, 2009, 12:34:38 PM
Yes, yes, yes, and yes.

Some use Windows Firewall (enabled automatically for some reason, regardless of my disabling it via services.msc) while one of the systems use ESET Smart Security. None of these applications ever interfered with networking.
Title: Re: Networking Issues
Post by: Ghastly on December 04, 2009, 01:09:57 PM
Yes, yes, yes, and yes.

Some use Windows Firewall (enabled automatically for some reason, regardless of my disabling it via services.msc) while one of the systems use ESET Smart Security. None of these applications ever interfered with networking.

So very very untrue. ESET Smart Security sometimes does - even with the firewall disabled.  I'm not saying that's your problem, but we have a corporate license for ESS, and after a couple of month's of hassling with it causing all sorts of inexplicable problems after we implemented (even when configured for minimal protection and even if disabled) we elected to downgrade all the systems to EAV.  This eliminated the networking problems.

If the system with ESET is being elected to be the Master Browser and then a portion of the traffic is being blocked, all kinds of oddities could happen.

<S>
Title: Re: Networking Issues
Post by: TilDeath on December 04, 2009, 04:54:39 PM
Ahhh ESET are your sharing within Eset and the Network connections set properly.  To check, double click your ESET icon in the tray,  In the lower left corner is shows the display mode change to "Advanced Mode".  Once in advanced mode Click on the "Setup" icon on the left side. On the right the last entry will be "Enter entire advanced setup tree..." click this then scroll down to Personal Firewall, choose "rules and zones" then choose "setup" make sure the radio button "Allow sharing" is enabled.  Still in personal firewall choose IDS and advanced options.  Make sure that the "Allow file and printer sharing in the Trusted zone" is checked.  Once this is checked on each system, again make sure that all the systems are members of the same work group and that there is a user name and password common on each system.  Reboot all and see if you can map to a drive.

TD
Title: Re: Networking Issues
Post by: Denholm on December 04, 2009, 11:52:57 PM
The only computer using ESS is my personal laptop. Even with the laptop removed from the network for days at a time the network shares remain inaccessible. Yes, sharing is enabled via ESS and because my laptop is rarely ever on our network I highly doubt it was marked as the Browse Master. Is there a particular way to enable authentication of users attempting to access Windows XP Home shares? Since XP home doesn't give you the option of altering the security policy, I never tried.
Title: Re: Networking Issues
Post by: TilDeath on December 05, 2009, 12:28:54 AM
Maybe I missed it but is there a common user account with the same password on all the systems?
Title: Re: Networking Issues
Post by: MrRiplEy[H] on December 05, 2009, 05:47:43 AM
Have you tried if you can ping the individual computers? That's the first test you should do to figure out if they have any link together in network. If no ping then you can troubleshoot in right direction.
Title: Re: Networking Issues
Post by: Auger on December 05, 2009, 07:29:46 PM
You really need to turn off all of the firewalls while you are trying to get this working.  Unplug from the Internet if turning the FW off makes you nervous.  It's not that you can't do file sharing with a FW on, but it makes it so much easier to troubleshoot.  If you can't even see shares on other PCs, it is most likely the firewall.
Title: Re: Networking Issues
Post by: 1701E on December 05, 2009, 08:40:29 PM
Typically when I can't get the computers to show each-other on the network there are a few things I check....(Using 2x XPs and a Vista):

-Check firewall: Is "Windows File and Printer sharing" checked as allowed.
-Check Adapter Priority settings: Is Ethernet/LAN set as 'First'.
-Check Protocols: Are all PCs up-to-date and using the same ones. (TCP/IPv6, etc.)
-Computer names: Are there any duplicate names (or IPs, annoying when that happens)
-File sharing: Is the 'File sharing' set as 'On' and on 'MSHOME' (or whatever name).
-Router: Are all PCs connected to the right Router (have 2) and showing as connected.

If it doesn't work after that for me I just give up and wait a few days and it randomly starts to work again. :)
Title: Re: Networking Issues
Post by: cattb on December 06, 2009, 11:14:13 AM
Denholm when you get the problem solved can you post the answer please.
Title: Re: Networking Issues
Post by: Denholm on December 06, 2009, 05:09:12 PM
Maybe I missed it but is there a common user account with the same password on all the systems?

No, not at this time. I'll see about doing that right now.

Have you tried if you can ping the individual computers? That's the first test you should do to figure out if they have any link together in network. If no ping then you can troubleshoot in right direction.

Yes, all responded in less than 5ms.

You really need to turn off all of the firewalls while you are trying to get this working.  Unplug from the Internet if turning the FW off makes you nervous.  It's not that you can't do file sharing with a FW on, but it makes it so much easier to troubleshoot.  If you can't even see shares on other PCs, it is most likely the firewall.

There's only one computer behind a software firewall, XP Pro SP3. It's rarely ever connected to the network. Windows firewall is the only other firewall available on the systems (except for Linux, naturally). However, it's disabled. Therefore there are no firewalls interfering.

Typically when I can't get the computers to show each-other on the network there are a few things I check....(Using 2x XPs and a Vista):

-Check firewall: Is "Windows File and Printer sharing" checked as allowed.
-Check Adapter Priority settings: Is Ethernet/LAN set as 'First'.
-Check Protocols: Are all PCs up-to-date and using the same ones. (TCP/IPv6, etc.)
-Computer names: Are there any duplicate names (or IPs, annoying when that happens)
-File sharing: Is the 'File sharing' set as 'On' and on 'MSHOME' (or whatever name).
-Router: Are all PCs connected to the right Router (have 2) and showing as connected.

If it doesn't work after that for me I just give up and wait a few days and it randomly starts to work again. :)

I'm going to look into that right now, some of those items I've already confirmed.

Denholm when you get the problem solved can you post the answer please.

I most certainly will! :)



EDIT:
For whatever reason, upon connecting a Vista/W7 Laptop to the network suddenly all the trouble-computers can access the Vista/W7's shares. However, the trouble-computers still fail to connect to each other.
Title: Re: Networking Issues
Post by: Denholm on December 06, 2009, 09:15:38 PM
Alright, I created new user accounts on all systems, the same user name and password combination now exists on all systems. Afterward I confirmed all systems are in the same workgroup, file and printer sharing is enabled, Windows Firewall is disabled, and shares existed for all systems. Upon testing this configuration, the only system's shares which could be accessed are those from the new Vista/W7 laptop. So, even with all the changes, the trouble-computers still can't connect to each other in order to view each others shares.

Let me try to describe the sharing situation in some more detail. Every computer in the network can access the Vista/W7 shares which I created today. However, none of the networked computers can open a connection to any of the trouble-computers to view their shares. Each computer is listed in the "View Workgroup Computers" panel, I just can't open a connection to any of the trouble-computers.
Title: Re: Networking Issues
Post by: cattb on December 07, 2009, 12:40:20 AM
http://social.technet.microsoft.com/Forums/en-US/itprovistanetworking/thread/8b228f88-ca0a-

http://www.omegacoder.com/?p=465

http://forums.pcworld.co.nz/showthread.php?t=54894

mabe this be some help mabe not
Title: Re: Networking Issues
Post by: Denholm on December 22, 2009, 10:00:36 PM
Problem fixed...

Well, I don't know why, but after formatting one of the trouble computers it seems the networking issues are resolved, to an extent. The remaining trouble-computer still has a "lock-out" attitude, yet it can access network shares on any other networked computer. My guess is that Windows was attempting to open a connection to the "Guest" account on the trouble-computers when in fact it didn't exist (disabled). Since the guest account isn't disabled on this fresh install (yet) the trouble-computer managed to connect to network shares immediately (for all accounts on the system... strange, I know). Next step is to alter the security policy and disable the guest account. If for some reason the trouble-computer won't connect (even when using proper login credentials), I'll try to back-track to see if one of the security policies is bothering the trouble-computer.
Title: Re: Networking Issues
Post by: Bino on December 23, 2009, 11:34:28 AM
Hi Delholm,

Check out this Description of the Guest account in Windows XP (http://support.microsoft.com/kb/300489) on the MS site.

Of note:

"...By default, on computers that are running Windows XP Professional and that have not joined to a domain, all incoming network connections are forced to use the Guest account..."
Title: Re: Networking Issues
Post by: Denholm on December 24, 2009, 11:27:25 AM
Well, that explains my situation to an extent. I always disable the guest account for additional security. I will still tinker around with the settings to see if perhaps I can establish a network connection with disabled guest accounts on both ends of the connection.
Title: Re: Networking Issues
Post by: Denholm on January 19, 2010, 02:31:29 PM
Well, I tinkered around with a few more settings and discovered that enabling "Network Access: Do not allow anonymous enumeration of SAM accounts and shares" seemed to lock out all valid network connection attempts (even when using login credentials from a local user). Upon disabling the security feature all network connection attempts were accepted.