.\" Copyright (c) 2004 Renzo Davoli
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.TH VDETAPLIB 1 "February 23, 2004" "Virtual Distributed Ethernet"
.SH NAME
vdetaplib \- Virtual Distributed Ethernet tap emulation library
.SH SYNOPSIS
No synopsis

.br
.SH DESCRIPTION
\fBvdetaplib\fP 
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):
.RS
.br
.B 
export LD_PRELOAD=/usr/local/lib/libvdetap.so
.RE
(csh, tchs syntax):
.RS
.br
.B
setenv LD_PRELOAD /usr/local/lib/libvdetap.so
.RE

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):
.RS
.br
.B
export VDEALLTAP=/tmp/vde.ctl
.RE
(csh, tchs syntax):
.RS
.br
.B
setenv VDEALLTAP /tmp/vde.ctl
.RE

It is also 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):
.RS
.br
.B
export tap0=/tmp/vde.ctl
.br
.B
export tap1=/tmp/myvde.ctl
.br
.B
export ppc=/tmp/ppc.ctl
.RE
(csh, tchs syntax):
.RS
.br
.B
setenv tap0 /tmp/vde.ctl
.br
.B
setenv tap1 /tmp/myvde.ctl
.br
.B
setenv ppc /tmp/ppc.ctl
.RE
.br

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.
.br
.SH SEE ALSO
.BR vde_switch (1),
.BR vdeq (1).
.br
.SH AUTHOR
VDE is a project by Renzo Davoli <renzo@cs.unibo.it>