3 Replies Latest reply on Jul 22, 2014 2:58 PM by chaas

    Low level driver question

    ScBem Community Member

      This one is probably best answered by the Driver development team.

       

      Recently I was having a problem with a network card in one of my user's laptops.  It is a Dell E6420 that I recently installed Windows 8.1 on.  After the upgrade, it showed "limited connectivity" on the wired NIC (wireless was fine).  I tried all kinds of things (even opened a ticket with Dell and got it escalated to their Executive Pro Support team).  Nothing seemed to work.  UNTIL - I started playing around with the Advanced settings and disabling some of them.  After much testing, I ended up with a fix.  If I disabled the TCP and UDP Checksum Offload (IPv4) it would do _something_ and reset the NIC.  If I re-enabled them, the problem did not return so, there was no direct correlation between the problem and the fix.  That must mean that when I clicked Apply to accept the changes the driver ran some kind of command or reset or something that fixed the problem and removed the "limited connectivity" icon.

       

      So, here's my question - what happens when I change those TCP and UDP Checksum Offload settings.  Somewhere in the driver program there must be a command that is run after clicking Apply that resets the stack or something.  I would like to know what that is. 

       

      Thanks for your help sating my curiousity.

        • Re: Low level driver question
          chaas Green Belt

          The issue you are seeing is likely due to a power saving feature on the switch/router to which the wired Ethernet is connecting. Log into the switch/router and disable the power saving features and test the connection again.  By disabling the power saving features the connection should stop being interrupted.

           

          Your direct question regarding changing the TCP and UDP settings would need to be asked of your system manufacturer; in this case, Dell.

           

          Best Regards,

          Casey H.

            • Re: Low level driver question
              ScBem Community Member

              Thanks Casey,

              This is a work computer plugged into a stack of cisco 3750's - no power save features.  It only affects the Dell e6420's that have Windows 8.1 on them (W7 computers are fine). 

                • Re: Low level driver question
                  chaas Green Belt

                  We did some more investigating for this question. It appears Dell does not provide technical specifications to that detail on their website. Going any further requires an account and machine ID codes (which I do not have).  The public site does not provide detailed information on which wired LOM is installed. Their site does say, "Gigabit I2xx or 825xx network controller". However, that can be one of several families of controllers.

                  Your best course of action at this time is to pursue your inquiry with Dell. Since this is their proprietary design, they will need to assist you with the LOM implementation.

                   

                  Best Regards,

                  Casey H.