dnet - Ethernet driver for DEC 21040, 21041, 21140  Ethernet




     The dnet Ethernet driver is a multithreaded, loadable, clon-
     able,  STREAMS  GLD  driver.  Multiple controllers installed
     within the system are supported  by  the  driver.  The  dnet
     driver  functions  include  controller initialization, frame
     transmit and receive, functional addresses, promiscuous  and
     multicast support, and error recovery and reporting.


     The cloning character-special device, /dev/dnet, is used  to
     access  all  DEC  21040/21041/21140 devices installed in the

     The dnet driver is dependent on /kernel/misc/gld, a loadable
     kernel  module  that  provides the dnet driver with the DLPI
     and STREAMS functionality required of  a  LAN  driver.   See
     gld(7D)  for more details on the primitives supported by the

     The device is  initialized  on  the  first  attach  and  de-
     initialized (stopped) on the last detach.

     The values returned by the driver in the DL_INFO_ACK  primi-
     tive  in response to a DL_INFO_REQ from the user are as fol-

        o  The  maximum  SDU  is  1500  (ETHERMTU  -  defined  in

        o  The minimum SDU is 0.

        o  The DLSAP address length is 8.

        o  The MAC type is DL_ETHER.

        o  The sap length  value  is  -2,  meaning  the  physical
           address  component is followed immediately by a 2-byte
           sap component within the DLSAP address.

        o  The  broadcast  address  value  is  the  Ethernet/IEEE
           broadcast address (FF:FF:FF:FF:FF:FF).

     Once  in  the  DL_ATTACHED  state,  the  user  must  send  a
     DL_BIND_REQ  to  associate a particular Service Access Point
     (SAP) with the stream.


     The PCI configuration process varies from system to  system.
     Follow the instructions provided by the vendor.

  Known Problems and Limitations
        o  On  multiport  cards  (exception:  Osicom   (Rockwell)
           RNS2340),  the  first  port  is  the top port. (On the
           Osicom RNS2340, the first port is the bottom port.)

        o  If the  dnet driver fails  to  determine  the  correct
           speed  and  duplex  mode  resulting in a corresponding
           drop in performance, set the  speed  and  duplex  mode
           using the dnet.conf file.

        o  The dnet driver incorrectly counts carrier lost or  no
           carrier  errors while in full-duplex mode. There is no
           carrier signal present when in full-duplex mode and it
           should not be counted as an error.

        o  Version 4 SROM formats are not supported.


     The  /kernel/drv/dnet.conf  file  supports   the   following

           For full duplex operation use full-duplex=1, for  half
           duplex  use full-duplex=0. Half-duplex operation gives
           better results on older 10mbit networks.

     speed For 10mbit operation use speed=10, for 100mbit  opera-
           tion  use  speed=100.  Certain  21140 based cards will
           operate at either speed. Use  the  speed  property  to
           override the 100mbit default in this case.


           character special device

           dnet configuration file


     See attributes(5) for descriptions of the  following  attri-

    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    | Architecture                | x86                         |


     attributes(5), dlpi(7P), gld(7D) streamio(7I)

     Writing Device Drivers

      STREAMS Programming Guide

     Network Interfaces Programmer's Guide

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