0 Replies Latest reply on Aug 6, 2012 8:16 AM by dan_schiro

    NET silently rejects any packets that are fragmented that require reassembly over the Maximum Transmission Unit (MTU) of the Ethernet/PPP device.

    dan_schiro

      Symptoms

      • NET silently rejects any packets that are fragmented that require  reassembly over the Maximum Transmission Unit (MTU) of the Ethernet/PPP  deve.
      • TFTP Server does not respond when using a block size option greater than the MTU

      Causes

        NET 5.1 now limits the maximum reassembly size.

        Upgrading from NET 4.5 to NET 5.1

      Solution

       

          Starting with NET 5.1, the maximum reassembly size is now limited by default, defaulting to  the MTU of the controller.  To change the default call to  NU_Set_Reasm_Max_Size.  It is best to calll this directly after the  device initialization.  For example:

          /* Initialize the ethernet device */
           if (NU_Init_Devices(DEMOI_Devices, 1) != NU_SUCCESS)
           {
               NU_Printf("NU_Init_Devices failed in DEMOI_Init_Task.\n");
               DEMOI_Exit(__LINE__);
           }

          /* Change the Maximum Reassembly Size.*/
           NU_Set_Reasm_Max_Size (DEMOI_Device_Name,65024);
       
           /* Now that NET initialization is complete set the even to start
              all the other tasks. */
           NU_Set_Events (&Init_Complete, NU_TRUE, NU_OR);