Please Help Network Gurus! QNX Fileshare not accessible on XP machine after Updates

[v2kai]

Hoping some of the beyond network gurus might be able to help me get to the root of a networking problem in my workplace. I'll do my best to give as much relevant info off the bat and can dig for more as required.

We've got a QNX based CNC controller hardwired to an XP Pro SP3 machine.

The XP machine has internet connected to the mobo ethernet adapter and an additional PCI ethernet adapter for the line to the CNC controller.
PCI Ethernet card in the XP machine is configured with a static IP as below:
Physical Address: E0-91-F5-94-2F-87
IP Address: 10.0.0.2
Subnet Mask: 255.255.255.0
Default Gateway: 10.0.0.0
DNS Server:
WINS Server:

The QNX CNC controller has static IP set to 10.0.0.1 as outlined by the install manual. Instructions in the CNC controller manual also requires the network to be renamed to PRECIX to communicate with the machine. This is set as well.

Until recently this whole setup worked fine allowing us to access the shared folder on the CNC controller via a mapped share at \\Precix5\files on the windows machine. Read/write access was available without issue.

After several windows automatic updates were applied overnight we can no longer access the shared folder. I am still able to successfully ping the CNC controller at 10.0.0.1 but that's about as far as I can get. When attempting to accessing the mapped share an error pops up as follows:



\\Precix5\files 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. The network path was not found.
At one point functionality was restored via system restore to a time prior to the problematic updates, however the updates were applied again by accident and system restore is no longer an option to revert the updates and resulting issue.

Any help troubleshooting this issue would be awesome. I apologize in advance for my n00bness when it comes to networking.

[eblend]

I am not very good with this stuff as I usually keep trying things until it works, but unless I am mistaken (could very well be)...you can't use the 10.0.0.0 as your default gateway if you plan on using 255.255.255.0 as a subnet mask.

with that subnet mask you can use 253 addresses, 10.0.0.0 would be your network address, 10.0.0.255 would be your broadcast address, and everything else would be your assumable addresses. Usually people use .1 or .254 for the gateway address if using the /24 subnet mask.

I am pretty sure your issue is somewhere in there. I will add more as I think of it.

EDIT: Hold on....I misread that, so the XP machine is not part of a bigger network, just on its own, and you are trying to access the presix5 from that machine only right?

What's the IP of the other NIC on there?

If your CNC controller is 10.0.0.1, your PC is 10.0.0.2 on one NIC, then you don't even need the gateway at all (perhaps this is causing issues, remove the gateway...especially a gateway that doesn't seem to be correct). Gateway is only used when you have to route to another subnet outside of the 10.0.0.0/24 range.

It sounds like your machine is multihomed, and you may have a routing issue somewhere, perhaps look into setting a static route....do you happen to have 10.0.0.anything used on your other NIC?

[v2kai]

Thanks, really appreciate the help eblend.

Ended up doing a ghetto fix to get things functional as fast as possible for the time being; wiped the machine, disabled updates to avoid the issue and got it all working again. A bit of a run around, but now I've got time to learn up on TCP/IP networking properly to troubleshoot the issue when time isnt a critical factor.

Any recommendations of good info to learn up?

[eblend]

Download some videos for ICND1..that should be sufficient to get a good udnerstanding of Networking basics.

[Mibz]

What happens when you ping "precix5"?

[revelations]

sounds like Windows XP changed the way files are shared recently (a la Windows 7) .... possibly permissions were reset or new ones added.

Hae you tried checking the properties of the shared folder yet?

[v2kai]

Originally posted by eblend
Download some videos for ICND1..that should be sufficient to get a good udnerstanding of Networking basics.

Thanks, I'll check that out.


Originally posted by Mibz
What happens when you ping "precix5"?

After my wipe and rebuild fix the machine has the required communications restored so I never actually got to attempt pinging precix5 when the issue was present; but I suspect it would have pinged just fine as did pinging the IP of the QNX machine directly. Attempting now with the fix in place and communication functionality restored, pinging precix5 and 10.0.0.1 are successful.


Originally posted by revelations
sounds like Windows XP changed the way files are shared recently (a la Windows 7) .... possibly permissions were reset or new ones added.

Hae you tried checking the properties of the shared folder yet?

It does seem that way, something in a security update on the XP machine. Dont have the ability to check permissions of the shared folder on the QNX machine. I only have limited access to configure the NIC on the QNX machine which is essentially just changing the IP address if I recall correctly.

[UndrgroundRider]

I'm surprised nobody has posted the correct answer yet. The problem is most likely related to a number of updates a while ago for Windows XP that disabled plain text authentication for network shares. Even if a given share doesn't need a password the handshake still fails.

The QNX system is obviously using an implementation of Samba and has the very old and deprecated setting of using plain text passwords. This hasn't been supported in newer versions of Samba for a long time.

The fix is to enable password encryption on the QNX machine (in the Samba configuration file smb.conf), or to uninstall the affected updates.

[v2kai]

Originally posted by UndrgroundRider
I'm surprised nobody has posted the correct answer yet. The problem is most likely related to a number of updates a while ago for Windows XP that disabled plain text authentication for network shares. Even if a given share doesn't need a password the handshake still fails.

The QNX system is obviously using an implementation of Samba and has the very old and deprecated setting of using plain text passwords. This hasn't been supported in newer versions of Samba for a long time.

The fix is to enable password encryption on the QNX machine (in the Samba configuration file smb.conf), or to uninstall the affected updates.

:clap: Beyond delivers yet again, thanks UndrgroundRider

quick google seems to point to a particular update. From the conversation details, does this look like the likely culprit then?
http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/a0695e57-dbb7-48b1-aedc-2f07011cfa18/

I'm not savvy enough to perform the required update to the QNX machine so looks like if this info is correct I can just avoid this update and we should be good hopefully.

[eblend]

Originally posted by UndrgroundRider
I'm surprised nobody has posted the correct answer yet. The problem is most likely related to a number of updates a while ago for Windows XP that disabled plain text authentication for network shares. Even if a given share doesn't need a password the handshake still fails.

The QNX system is obviously using an implementation of Samba and has the very old and deprecated setting of using plain text passwords. This hasn't been supported in newer versions of Samba for a long time.

The fix is to enable password encryption on the QNX machine (in the Samba configuration file smb.conf), or to uninstall the affected updates.

Good call, didn't realize they had updates for XP for that...our shop is pure Windows 7 as of last weekend, migration completed, haven't personally used XP for what....6 years? Hahah, every time I touch an XP machine now, I have no idea where to go, feels like NT to me :D

[v2kai]

Originally posted by eblend


Good call, didn't realize they had updates for XP for that...our shop is pure Windows 7 as of last weekend, migration completed, haven't personally used XP for what....6 years? Hahah, every time I touch an XP machine now, I have no idea where to go, feels like NT to me :D

Yea my shop is behind the curve to put it lightly. Prior to me coming to the company four years ago fax was the way of the future and emails were considered unreliable black magic lol :facepalm: