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Network diagnostics for dummies..

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  • Network diagnostics for dummies..

    Hi folks.
    We have a customer site that is experiencing some issues.
    It was first reported to us as their Internet based CRM solution running slow, so we passed it onto the supplier who denied that their servers having about 6 times as much lag as you'd normally expect was any problem at all.
    We kept pushing it with them as we would log onto their SBS server, run some bandwidth tests and see absolutely nothing wrong.

    Then the other day the client decided to give us some more information about the issue (why they didn't give us all the info in the first place I don't know).

    Apparently computers are intermittently getting long lag on some pages and then for a few minutes they will simply get the page cannot be displayed errors. They are unable to tell us whether or not everyone has the same issue at the same time.

    So my thoughts were maybe router (a Thomson Speedtouch, about a year old) or ISP.

    Then they threw something else in the mix which doesn't make much sense. Apparently they are intermittently getting prompts from computers asking them to dial up to the Internet. To me this immediately suggested that the network connection was going down and that the switch (24 port Netgear) must be dropping ports BUT I was then told that when this happens the PC can still browse the network shares on the server.

    That stumped me as I thought that Internet Explorer only tried to dial if IE was set to dial when no network was present and the network link physically dropped.

    So what we're face with is maybe having the server deploy some kind of app or script that can run every 10 minutes or so on all the PCs and do some network tests both locally and over the Internet to get some usable diagnostics info. Does anyone know of any solution that we can use to get such info?


  • #2
    Re: Network diagnostics for dummies..

    run a full security evaluation on the network....
    Please do show your appreciation to those who assist you by leaving Rep Point


    • #3
      Re: Network diagnostics for dummies..

      I'd just use something as simple server monitoring service to ping the modem and alert you via email if the ping dies. Set up the freeware version of PingPlotter on a couple of computers off of the customer's site and ping the customer's modem to see what data you gather. Also, set it up on a machine on site set to ping something like Google or the CRM app's site to see if there are any hops that are problematic.
      Wesley David
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      • #4
        Re: Network diagnostics for dummies..

        Try running a sniffer as close to one of the PC that is have the issue with the application. You can use something like wireshark. Just set a capture filter on a particular users mac address see how the one of the pc's interacts with said server.

        Packets never lie


        • #5
          Re: Network diagnostics for dummies..

          The problem is that things are happening all over the network intermittently. We've never been on site when it happens so need something to collect info periodically.

          I came up with my own solution.

          Share on the server with two folders:


          Results is empty and is where the results .txt files will get copied to.
          Scripts contains 3 files:

          The first, setup.bat is put into Active Directory as a startup script:

          @echo off
          if exist "C:\netdiag" goto skipnetdiag
          md netdiag
          cd netdiag
          if exist "C:\netdiag" goto skipresults
          md results
          if exist "C:\netdiag" goto skipscripts
          md scripts
          cd scripts
          copy \\server\share\scripts\* *
          schtasks /delete /f /tn MCSNetDiag
          schtasks /create /ru SYSTEM /sc MINUTE /mo 10 /tn MCSNetDiag /TR c:\netdiag\scripts\runner.bat
          This copies things locally and then sets up a scheduled task to run every 10 minutes as SYSTEM that runs the second batch file runner.bat:

          @echo off
          set today = %DATE:~6,4%%DATE:~3,2%%DATE:~0,2%%TIME:~0,2%%TIME:~3,2%
          call c:\netdiag\scripts\netdiag.bat > c:\netdiag\results\%TODAY%.txt
          if exist "\\server\share\results\%COMPUTERNAME%" goto skipcompname
          md \\server\share\results\%COMPUTERNAME%\
          copy c:\netdiag\results\*.* \\server\share\results\%COMPUTERNAME%\*.* /y
          This is simply to call the file, capture the output and then copy it to the server. If the network is down, the output will stay and be copied the next time.

          The final batch file that actually does some diagnostics is netdiag.bat:

          @echo off
          netsh diag show test
          netsh diag connect iphost 80
          netsh diag connect iphost 80
          netsh diag connect iphost 80
          netsh diag connect iphost router.web.admin.interface 80
          I'm sure you could probably do something more fancy with better testing tools that doesn't log unless there's any errors but I don't know of anything like that offhand. Can anyone advise of something so we don't end up with a bazillion logfiles to sift through?


          • #6
            Re: Network diagnostics for dummies..

            I would try something simple like a continuos ping to the site that no-one knows about and see if you can find anything from that.

            If they complain about it then you can look through the logs to see if there is a delay during the day.

            You could also get them to contact you ASAP in the event of a drop out and get dialed in to check it out using ping, tracert etc to see what it going on.

            Thre could be something simple like a dodgy route statement at the ISP side whereby one router sends it one way and another sends it another way.