# netdefault(8)

    NAME
         netdefault - select the default TCP/IP network

    SYNOPSIS
         netdefault [-n] sample-device

    DESCRIPTION
         Netdefault selects the default network to use of one of the four networks
         a Minix system can be connected to.  One can choose between two different
         ethernet networks and two different pseudo IP networks that can  be  used
         to make a connection over a serial line.

         The sample-device is the name of one of the network devices  in  /dev  to
         use  as the default network.  This device and devices for other protocols
         for the same network will be linked to the default device names  for  the
         network.   The network utilities access the default network through these
         devices, unless a different device is chosen by  setting  an  environment
         variable, or a by a command line switch.

         Use the -n flag to only show what would be done, instead of really  doing
         it.

      Options and environment to change the default
         Many TCP/IP programs implement  the  following  options  and  environment
         variables  to  change the default devices set by netdefault.  The options
         are only implemented for low level programs where it makes sense to  name
         a  network  device.  The environment variables are used in all code.  You
         can run a process and all its children connected to a  different  network
         by setting four environment variables.

         ETH_DEVICE=device
         -E device
              Device to  use  as  raw  ethernet  device  instead  of  the  default
              /dev/eth.

         PSIP_DEVICE=device
         -P device
              Pseudo IP device to use instead of /dev/psip.

         IP_DEVICE=device
         -I device
              IP device to use instead of /dev/ip.

         TCP_DEVICE=device
         -T device
              TCP device to use instead of /dev/tcp.

         UDP_DEVICE=device
         -U device
              UDP device to use instead of /dev/udp.

    FILES

         /dev/eth[01]      First and second raw ethernet.

         /dev/psip[23]     First and second Pseudo IP network.

         /dev/ip[0123]     IP  devices  for  two  ethernets  and  two  Pseudo   IP
                           networks.

         /dev/tcp[0123]    TCP devices for same four networks.

         /dev/udp[0123]    UDP devices.

         /dev/eth, /dev/psip, /dev/ip, /dev/tcp, /dev/udp
                           Devices for the default network, links to  the  devices
                           above.   /dev/eth  is  only  present if ethernet is the
                           default, /dev/psip only for pseudo IP.

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

    AUTHOR
         Kees J. Bot (kjb@cs.vu.nl)