---
name: "vdetaplib"
section: "1"
platform: "linux"
package: "vde2"
version: "2.3.3-10"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/vdetaplib"
---

# vdetaplib(1)

Virtual Distributed Ethernet tap emulation library

## NAME

vdetaplib - Virtual Distributed Ethernet tap emulation library

## SYNOPSIS

No synopsis

## DESCRIPTION

**vdetaplib**  is a library that emulates tap (tuntap level2 interface, see in kernel sources Documentation/networking/tun.c) and connects tap virtual interfaces to vde networks.

To use it, the libvdetab.so library must be preloaded (sh, ksh or bash syntax):

**export LD\_PRELOAD=/usr/lib/vde2/libvdetap.so**

(csh, tcsh syntax):

**setenv LD\_PRELOAD /usr/lib/vde2/libvdetap.so**

If you want to divert all tap requests to a single vde\_switch set the variable VDEALLTAP to the vde socket. \
 (sh, ksh or bash syntax):

**export VDEALLTAP=/tmp/vde.ctl**

(csh, tcsh syntax):

**setenv VDEALLTAP /tmp/vde.ctl**

It is possible to set each single interface to different vde\_switches by setting the environment variable with the same name of the interface.\
 (sh, ksh or bash syntax):

**export tap0=/tmp/vde.ctl**\
 **export tap1=/tmp/myvde.ctl**\
 **export ppc=/tmp/ppc.ctl**

(csh, tcsh syntax):

**setenv tap0 /tmp/vde.ctl**\
 **setenv tap1 /tmp/myvde.ctl**\
 **setenv ppc /tmp/ppc.ctl**

It is also possible to specify **port**, **group** or **mode** for a given interface setting environment variables as in the following example.\
 (sh, ksh or bash syntax):

**export tap0\_port=5**\
 **export tap0\_group=vde-net**\
 **export tap0\_mode=0660**

(csh, tcsh, syntax):

**setenv tap0\_port 5**\
 **setenv tap0\_group vde-net**\
 **setenv tap0\_mode 0660**

The variable to set the specific interface is checked first then VDEALLTAP. VDEALLTAP thus works as a default choice for the vde switch to be used. If VDEALLTAP is not set and there is no specific environment variable (and for tun -- IFF\_TUN interfaces) the kernel provided interface is used. In this latter case access to /dev/net/tun is required, generally root access.\

## NOTICE

Virtual Distributed Ethernet is not related in any way with www.vde.com ("Verband der Elektrotechnik, Elektronik und Informationstechnik" i.e. the German "Association for Electrical, Electronic & Information Technologies").

## SEE ALSO

[**vde\_switch**(1)](/vde_switch/1.md), [**vdeq**(1)](/vdeq/1.md).\

## AUTHOR

VDE is a project by Renzo Davoli \<renzo@cs.unibo.it\>