---
name: "vmnet"
section: "1"
platform: "linux"
package: "vmnet"
version: "0.4-1"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/vmnet"
---

# vmnet(1)

A simple virtual networking program

## NAME

vmnet — A simple virtual networking program

## SYNOPSIS

**vmnet**

## DESCRIPTION

This manual page documents briefly the  **vmnet** program.

This manual page was written for the **Debian GNU/Linux** distribution  because the original program does not have a manual page.  Instead, it has a README file; see below.

This program has been written to implement virtual  networking support for the Hercules S/390 simulator, but it is  intentionally generic in its functionality, so any other virtual  machine simulator/emulator program could potentially use  it.

The function is quite simple: The virtual machine simulator  program starts VMnet and talks the SLIP protocol with it over  stdin/out.  VMnet sets up a SLIP connection on the host system,  talking over a pseudo-tty to the VMnet program.  Once things  have been set up, VMnet simply copies the data streams between  stdin/out and the SLIP psuedo-tty in both directions.  Thus, the  virtual machine has a direct SLIP connection with the host,  without needing to worry about root privileges, pseudo-ttys,  access rights, etc.

## CONFIGURATION

You will need to create a configuration file /etc/vmnet.conf  with entries that look like:

user    remote-ip       local-ip        command

Each entry/line in the file represents a pair of IP  addresses that a given user may use.  Lines starting with "#"  are ignored.

The user field identifies the user by her login name.

The remote-ip field contains the remote IP address, as seen  from the SLIP connection on the host, i.e. the IP address of the  virtual machine.

The local-ip field contains the local IP address, as seen from  the SLIP connection on the host.  You may have to specify this  address as the "remote address" or "gateway" on the virtual  machine.

The command field gives a command to be executed when the  SLIP interface is brought up or down.  The command should accept  three arguments: (up\|down), remote-ip, local-ip.  This can be  used to perform any special actions, like routing, proxy-arp,  etc, as needed.  You *must* specify a valid  command here.  If you don't want anything done, "/bin/true" will  do.

## OPERATION

The user will normally not run the vmnet program manually,  unless he wants to practice his skills at reading and typing  SLIP packets.  The intended usage is to have the virtual machine  start vmnet at the appropriate time so it can connect the  stdin/stdout of vmnet to its network device simulation.  When  VMnet is started, it expects one line of input, containing the  remote-ip address to use, followed by SLIP traffic.  VMnet does  not produce any user-readable output on stdout.

## SEE ALSO

/usr/share/doc/vmnet/README

## AUTHOR

vmnet was written by Willem Konynenberg  wfk@xos.nl

This manual page was written by Matt Zimmerman mdz@debian.org for  the **Debian GNU/Linux** system (but may be used by others).  Permission is  granted to copy, distribute and/or modify this document under  the terms of the GNU Free Documentation  License, Version 1.1 or any later version published by the Free  Software Foundation; with no Invariant Sections, no Front-Cover  Texts and no Back-Cover Texts.