man(1) Manual page archive


     ETHERNET(4)                                           ETHERNET(4)

     NAME
          ethernet - Ethernet interface

     SYNOPSIS
          #include <sys/enio.h>
          #include <sys/ethernet.h>

     DESCRIPTION
          There are drivers for several hardware interfaces to Ether-
          net.  All have the same programming interface.

          There are eight software channels for each hardware device.
          A channel sends and receives packets for a single Ethernet
          interface; hence eight protocols may be used independently
          on the same device.  If a channel is open, it may not be
          opened again.

          Read and write deal in Ethernet packets, consisting of a
          header followed by no less than 46 but no more than 1500
          bytes of data.  The header, defined in <sys/ethernet.h>, is
          as follows:

          #define   ETHERALEN 6    /* bytes in an ethernet address */

          struct etherpup {
               unsigned char dhost[ETHERALEN];    /* destination address */
               unsigned char shost[ETHERALEN];    /* source address */
               unsigned short type;     /* protocol type */
          };

          The protocol type is in the network's byte order, most sig-
          nificant byte first.

          Read on a channel returns at most one complete packet.  If
          only part of a packet fits in the read buffer, successive
          reads return the remainder.  Write should be given a single
          complete packet; dhost and type must be filled in.  The sys-
          tem supplies shost.

          There are a few ioctl calls, defined in <sys/enio.h>:

          ENIOTYPE The third argument points to a short integer; use
                   that as the protocol type for this channel.

          ENIOADDR The third argument points to a six-character
                   buffer; copy the hardware address of this interface
                   there.

          Minor device numbers 0-7 are the eight channels of the first
          hardware device of a given type; 8-15 are the second device,

     ETHERNET(4)                                           ETHERNET(4)

          and so on.  File names usually end in two digits, like
          /dev/il13 for the fourth channel of the second Interlan
          device.

     FILES
          Interlan NI1010A devices
          DEQNA devices
          DEBNA devices

     SEE ALSO
          internet(3), ipconfig(8)

     BUGS
          The DEQNA driver fills in the protocol type field in trans-
          mitted packets; other drivers don't.