man(1) Manual page archive


     LANCE(3)                                                 LANCE(3)

     NAME
          lance - LANCE Ethernet device

     SYNOPSIS
          bind -a #l /net

          /net/ether/clone
          /net/ether/[0-7]
          /net/ether/[0-7]/data
          /net/ether/[0-7]/ctl
          /net/ether/[0-7]/stats
          /net/ether/[0-7]/type

     DESCRIPTION
          The LANCE Ethernet interface is a directory containing 9
          stream directories: one for each of 8 Ethernet packet types
          and a clone file.

          Each stream directory contains files to control the stream,
          receive and send data, and supply statistics.  Incoming Eth-
          ernet packets are demultiplexed by packet type and passed up
          the corresponding open stream.  Reading from the data file
          reads packets at the head of the stream.  A read will termi-
          nate at packet boundaries.  Each write to the data file
          causes a packet to be sent.  The Ethernet address of the
          interface is inserted into the packet header as the source
          address.

          A stream is assigned a packet type by opening its ctl file
          and writing connect n where n is a decimal integer constant
          identifying the Ethernet packet type.  A value of -1 stands
          for all types.  If multiple streams are assigned to a given
          packet type a copy of the packet is passed up each stream.

          Reading the type file returns the decimal value of the
          assigned Ethernet packet type.  Reading the stats file
          returns status information and the Ethernet address of the
          interface.

          An interface normally receives only packets whose destina-
          tion address is that of the interface or is the broadcast
          address, ff:ff:ff:ff:ff:ff.  The interface can be made to
          receive all packets on the network by writing the string
          promiscuous to the ctl file. The interface remains promiscu-
          ous until the control file is closed.  The extra packets are
          passed up only streams of type -1.

     SOURCE
          /sys/src/9/port/devlance.c