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  • Intermittent Dropping Network Mappings

    We carried out an upgrade of client PCs from Windows XP SP3 to Windows 7. Profiles were migrated to Windows 7 profiles resulting in the appropriate v2 profile folders being created. They are all set as roaming.

    There is a Windows 2003 R2 file/SQL server, w2k8 server used for Terminal Services and now print services and a MOSS front end server (w2k3 server), which uses the SQL server for its databases.

    The first machines migrated were tested and no problems were found. After a week, we then progressed the other migrations.

    After a couple of weeks, we started to experience issues with Printers and network drive mappings becoming unavailable. They still appeared but the computer drive mappings had red crosses and the Printers were opaque. They would sometimes come back by themselves, otherwise, restarting the PC resolves the issue until it comes back again.

    This doesn't effect all staff. It seems to be limited to the same 10 that are in different areas, different switches, different departments and are in areas where other users have never had the problem.

    When the Computer drive mappings drop, all other services are fine. I have created a workaround by configuring a batch file using 'net use' to remove all existing drive mappings and then re-map them, they come back ok. If users double click on one of the dropped shares, they receive a message indicating that the 'name is already in use'. However, when the computer drive mappings have dropped (red crosses are present), a network location mapping to the same share and using the same UNC path, continues to allow connection. Furthermore, a shortcut on the desktop using a UNC path allows the connection and a UNC path used within the run command, also brings up the share. Also, the drive mapping drops seems to happen more when the computer has been left idle.

    Here is a bulleted list of steps so far.
    • Moved all printer shares to a w2k8 server and re-mapped client PCs to the new location - problem resolved for printers.
    • Altered the drive mappings script to use the IP address instead of the DNS name of the share.
    • Set the Local security policy (at domain level) for the Network security: LAN Manager authentication level to Send LM & NTLM responses
    • Created a local profile for a user and not based on their roaming profile.
    • Created a share on the w2k8 server and this drops as well when the problem occurs.
    • Uninstalled AV on the client PC and SQL server. (for temporary testing)
    • Set the w2k3 idle timeput setting to -1, so the default of 15 mins wouldn't contribute to the share drops.
    • Checked logs at the time a user was effected. This did not shed any further light.
    • Inpsected the server's NETSTAT status at the time of drives dropping.
    Any help or advice would be appreciated. It is a baffling one and the worrying part is that some staff, who have never had the problem, are starting to do so.
    Last edited by Virtual; 21st June 2010, 15:00. Reason: grammar changes

  • #2
    Re: Intermittent Dropping Network Mappings

    Good to know someone out there posts questions with plenty of detail

    Not too sure what could be causing that, but one thought did come to mind - when you say you've upgraded to Windows 7, did you upgrade the OS or install 7 from scratch?

    Are the servers and workstations all up to date in terms of Windows patches and hardware drivers?
    Gareth Howells

    BSc (Hons), MBCS, MCP, MCDST, ICCE

    Any advice is given in good faith and without warranty.

    Please give reputation points if somebody has helped you.

    "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

    "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

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    • #3
      Re: Intermittent Dropping Network Mappings

      Further to the post, I also tried disabling a scheduled task that runs.

      Task Scheduler Library, Windows, Diagnosis.

      I still get the same problem.

      Comment


      • #4
        Re: Intermittent Dropping Network Mappings

        A colleague has suggested I ask you what switchgear you have in place; they had a similar issue caused by a bug in 3Com's firmware.
        Gareth Howells

        BSc (Hons), MBCS, MCP, MCDST, ICCE

        Any advice is given in good faith and without warranty.

        Please give reputation points if somebody has helped you.

        "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

        "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

        Comment


        • #5
          Re: Intermittent Dropping Network Mappings

          Thanks for the post back and your comment.

          They were brand new Windows 7 PCs and not an in-place upgrade.

          All servers have the latest patches and hardware drivers and I have compared a PC that does and doesn't have the problem and hardware drivers have been identical. The computer AD accounts are in the same OU and users have their drive mappings created via a script that runs at user logon. The same GPOs apply to the same users in a certain AD OU where some staff will have the intermittant problem and others not.

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          • #6
            Re: Intermittent Dropping Network Mappings

            They are 2 x Linksys 48 port switches.

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            • #7
              Re: Intermittent Dropping Network Mappings

              Are they managed or unmanaged?
              Gareth Howells

              BSc (Hons), MBCS, MCP, MCDST, ICCE

              Any advice is given in good faith and without warranty.

              Please give reputation points if somebody has helped you.

              "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

              "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

              Comment


              • #8
                Re: Intermittent Dropping Network Mappings

                Cheers for your attention to the post. Unmanaged.

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                • #9
                  Re: Intermittent Dropping Network Mappings

                  I've had this one too, we upgraded all clients to Windows 7 Enterprise x64 with the File and Print Servers still at Server 2003 R2. Never did get to the bottom of it but it went away when we migrated the FP server to 2008 R2.

                  All of the research we did pointed to Network Location Awareness on the 7 clients being the issue. I have a suspicion it may be to do with 2008 and 7 defaulting to IPv6 DNS servers. Like I said though, we haven't had it again so I stopped looking into it.
                  BSc, MCSA: Server 2008, MCSE, MCSA: Messaging, MCTS
                  sigpic
                  Cruachan's Blog

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                  • #10
                    Re: Intermittent Dropping Network Mappings

                    Thanks Cruachan. We are considering the same.

                    I also noticed an auto-tuning setting enabled on Windows Vista and Windows 7 and was wondering if that could be the issue. I am going to test.
                    Last edited by Virtual; 22nd June 2010, 09:46.

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                    • #11
                      Re: Intermittent Dropping Network Mappings

                      Interesting!

                      I have 3 Win7 clients on my network and a couple of them were experiencing this issue. However, after reading this, it suddenly occurred to me that the people that use those machines have not reported a problem recently. This may be because I moved all our data from a 2003 to 2008 server about 5/6 weeks ago.
                      A recent poll suggests that 6 out of 7 dwarfs are not happy

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                      • #12
                        Re: Intermittent Dropping Network Mappings

                        Ah, ok. Thanks Blood. It is bazaar. One user that had the issue resolved has suddently had it re-occur again today. An upgrade may be in order.

                        Comment


                        • #13
                          Re: Intermittent Dropping Network Mappings

                          It was very random how it affected people for us too. The MD seemed to have it worst, although that may be because he used the shared folders the most.

                          We found a forum posting in the MSDN groups suggesting turning off NLA to resolve the issue. Not only did that not fix it it also put a big red X on the NIC icon in the System Tray which really bugged everybody.
                          BSc, MCSA: Server 2008, MCSE, MCSA: Messaging, MCTS
                          sigpic
                          Cruachan's Blog

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                          • #14
                            Re: Intermittent Dropping Network Mappings

                            Bad news

                            The issue occurred again today on one of the Win7 clients.

                            The share that became unavailable was a DFS share - DFS is hosted on a 2003 Standard Edition DC, and the data is on a Win2008 file server.

                            Mapping one of the shares collected by the DFS node via the traditional method - navigate to the server and right-click>Map network drive - results in a share that is accessible.

                            The network sharing centre shows the network as a domain.

                            I had not created DFS on the Win2008 DC because I thought it best to leave it alone. I may have to remove it from the 2003 machine and install it on the 2008 machine. There goes a saturday morning...
                            A recent poll suggests that 6 out of 7 dwarfs are not happy

                            Comment


                            • #15
                              Re: Intermittent Dropping Network Mappings

                              Perhaps also look at the configuration of the nic, might be it jumps to powersaving al of a sudden either by driver setting or because windows is idling for to long.

                              In the last case you shouldnt change anything, just tell your users they should work harder =-)
                              Please give points where appropriate

                              <I dont create ready scripts for you, but I'm willing to point you in the right direction>

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