INET(8)INET(8)NAME
inet, inet.conf - TCP/IP server
SYNOPSISinetDESCRIPTION
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 han‐
dled by driver "DP8390" instance 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 uses a simple line-based format.
Each network definition has to be fully on its own line.
Empty lines and lines that start with a `#' symbol are
ignored. The following network definitions are possible:
ethN driver instance {options};
This sets up an ethernet with device name
/dev/ethN, built on the given ethernet device
driver with the given instance number. (If there
are two network cards of the same type then they
will be managed by instance 0 and 1 of the corre‐
sponding driver.)
ethN vlan id ethM {options};
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. Like‐
wise a packet on that ethernet carrying the appro‐
priate 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.
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 with‐
out 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 ALSOip(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>
INET(8)
