VDETAPLIB(1) General Commands Manual VDETAPLIB(1)

vdetaplib - Virtual Distributed Ethernet tap emulation library

No synopsis

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.

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").

vde_switch(1), vdeq(1).

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

December 6, 2006 Virtual Distributed Ethernet