# inet(8)

    NAME
         inet - TCP/IP server

    SYNOPSIS
         inet

    DESCRIPTION
         Inet is the TCP/IP server.  It is a device driver that interfaces between
         the  file server and the low level ethernet device driver.  The interface
         to this server is described in ip(4).

         Inet  starts  as  a  normal  process,  reads  a  the  configuration  file
         /etc/inet.conf to see what it should do, and uses a few special low level
         system  calls  to  turn  itself  into  a  server.   The  format  of   the
         configuration file is as follows:

      Configuration
         The inet configuration file is fairly simple, here is an example:

              eth0 DP8390 0 { default; };
              psip1;

         It tells that network 0 (the one containing devices eth0, ip0,  tcp0  and
         udp0) uses the ethernet device driver handled by task "DP8390" at port 0.
         This network is marked as the default network, so most  programs  use  it
         through the unnumbered devices like /dev/tcp or /dev/udp.  Network 1 is a
         Pseudo IP network that can be used for a  serial  IP  over  a  modem  for
         instance.

         The configuration file may look  like  a  common  configuration  file  as
         described  by  configfile(5),  but  it  is currently just a simple subset
         allowing only what you see here.  The following network  definitions  are
         possible:

         ethN task port {options};
              This sets up an ethernet with device name /dev/ethN,  built  on  the
              given  ethernet device driver at the given port at that driver.  (If
              a network driver manages two network cards then they are at  port  0
              and 1.)

         ethN vlan id ethM {options};     (Minix-vmd only)
              The ethernet ethN uses VLAN number id and is built on ethernet ethM.
              A  packet given to this network has a VLAN tag prefixed to it and is
              then handed over to another ethernet for transmission.   Likewise  a
              packet  on  that ethernet carrying the appropriate VLAN tag has this
              tag removed and is sent on  to  this  network.   The  VLAN  ethernet
              behaves  like  an  ordinary  ethernet  as  far  as  applications are
              concerned.

         psipN {options};
              Creates pseudo IP network /dev/psipN,  usable  for  IP  over  serial
              lines, tunnels and whatnot.

    OPTIONS
         Some options can be given between braces.  Minix only understands one  of
         these options, "default".  Minix-vmd does them all, of course.

         default;
              Mark this network as  the  default  network.   Exactly  one  of  the
              networks  must be so marked.  When inet is started it will check and
              create all the necessary network devices before becoming  a  server.
              To  know  what major device number to use it checks /dev/ip, so that
              device must already exist.  It can be created by MAKEDEV if need be.

         no ip;
         no tcp;
         no udp;
              These options turn the IP, TCP, or UDP layer  off.   Inet  will  not
              enable  the  devices  for these layers, and will deactivate code for
              these layers.  Disabling IP will also disable TCP  or  UDP,  because
              they  need  IP  to function.  An ethernet without an IP layer can be
              used as for stealth listening.  An IP network without TCP or UDP can
              be  used to pester students into creating the missing functionality.
              Keeps them off the streets, and maybe they'll learn something.

    SEE ALSO
         ip(4), boot(8).

    NOTES
         The number of networks that can be defined are 2  (Minix-86),  4  (Minix-
         386)  or  16  (Minix-vmd).   This  limits  both  the total number and the
         highest device number you can use.

         Getting a network administrator to give you a trunk or multi-VLAN port to
         run  multiple  networks  on  can be a challenge.  It questions their idea
         that VLANs are separate networks, while in reality it  is  just  one  big
         ethernet.

    ACKNOWLEDGMENTS
         Cindy Crawford, for providing invaluable help debugging this server.

    AUTHOR
         Code:    Philip Homburg <philip@cs.vu.nl>
         Manual:  Kees J. Bot <kjb@cs.vu.nl>