.\"	$OpenBSD: mpw.4,v 1.9 2021/03/18 14:22:04 kn Exp $
.\"
.\" Copyright (C) 2015 Rafael Zalamena <rzalamena@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: March 18 2021 $
.Dt MPW 4
.Os
.Sh NAME
.Nm mpw
.Nd MPLS Ethernet pseudowire
.Sh SYNOPSIS
.Cd "pseudo-device mpw"
.Sh DESCRIPTION
The
.Nm
interface is used to create an MPLS Ethernet layer 2 tunnel between
two points.
.Pp
An
.Nm
interface can be created at runtime using the
.Sy ifconfig Nm Ns Ar N Cm create
command or by setting up a
.Xr hostname.if 5
configuration file for
.Xr netstart 8 .
The interface itself can be configured with
.Xr ifconfig 8 .
.Pp
The local MPLS label, the remote MPLS label and neighbor, use of
pseudowire control words, or flow-aware transport are normally
configured after negotiation with a remote system using
.Xr ldpd 8 ,
but it is also possible to configure them manually using
.Xr ifconfig 8 .
.Sh EXAMPLES
Create a pseudowire with local label 20 and remote label 21 on
neighbor 10.254.0.1:
.Bd -literal -offset indent
# ifconfig mpw5 create
# ifconfig mpw5 mplslabel 20 pweneighbor 21 10.254.0.1
# ifconfig mpw5 up
.Ed
.Pp
Enable the use of the Pseudowire Emulation Edge-to-Edge (PWE3)
Control Word, and disable the use of a Flow label for Flow-Aware
Transport of Pseudowires:
.Bd -literal -offset indent
# ifconfig mpw5 pwecw -pwefat
.Ed
.Pp
.Nm mpw
interfaces may be used to build a Virtual Private LAN Service
(VPLS) with
.Xr bridge 4 .
A VPLS is constructed with a full mesh of MPLS pseudowire tunnels
between all peers, but this introduces loops in the topology.
To prevent broadcast packets received from the VPLS being forwarded
to its peers, all the pseudowire interfaces can be configured to
enforce the split-horizon forwarding rule by adding them to the
same protected bridge domain.
Different VPLS meshes can be joined together on the same bridge
using different identifiers for their protected domains:
.Bd -literal -offset indent
# ifconfig mpw10 create up
# ifconfig mpw11 create up
# ifconfig mpw12 create up
# ifconfig bridge0 create
# ifconfig bridge0 add em2
# ifconfig bridge0 add mpw10 add mpw11 add mpw12
# ifconfig bridge0 protected mpw10 1
# ifconfig bridge0 protected mpw11 1
# ifconfig bridge0 protected mpw12 1
.Ed
.Sh SEE ALSO
.Xr mpe 4 ,
.Xr mpip 4 ,
.Xr hostname.if 5 ,
.Xr ifconfig 8 ,
.Xr ldpd 8 ,
.Xr netstart 8
.Rs
.%A S. Bryant
.%A P. Pate
.%D March 2005
.%R RFC 3985
.%T Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture
.Re
.Pp
.Rs
.%A S. Bryant
.%A G. Swallow
.%A L. Martini
.%D February 2005
.%R RFC 4385
.%T Pseudowire Emulation Edge-to-Edge (PWE3) Control Word \
for Use over an MPLS PSN
.Re
.Pp
.Rs
.%A S. Bryant
.%A C. Filsfils
.%A U. Drafz
.%A V. Kompella
.%A J. Regan
.%A S. Amante
.%D November 2011
.%R RFC 6391
.%T Flow-Aware Transport of Pseudowires over an MPLS Packet Switched Network
.Re
.Sh HISTORY
The
.Nm
kernel interface first appeared in
.Ox 5.8 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Rafael Zalamena Aq Mt rzalamena@openbsd.org .