MPLS Ethernet pseudowire
mpw interface is used to create an
MPLS Ethernet layer 2 tunnel between two points.
mpw interface can be
created at runtime using the
create command or by setting up a
hostname.if(5) configuration file for
netstart(8). The interface itself can be configured with
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 ldpd(8), but it is also possible to configure them manually using ifconfig(8).
Create a pseudowire with local label 20 and remote label 21 on neighbor 10.254.0.1:
# ifconfig mpw5 create # ifconfig mpw5 mplslabel 20 pweneighbor 21 10.254.0.1 # ifconfig mpw5 up
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:
# ifconfig mpw5 pwecw -pwefat
mpw interfaces may be used to build a
Virtual Private LAN Service (VPLS) with
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:
# 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
mpe(4), mpip(4), hostname.if(5), ifconfig(8), ldpd(8), netstart(8)
S. Bryant and P. Pate, Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture, RFC 3985, March 2005.
S. Bryant, G. Swallow, and L. Martini, Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN, RFC 4385, February 2005.
S. Bryant, C. Filsfils, U. Drafz, V. Kompella, J. Regan, and S. Amante, Flow-Aware Transport of Pseudowires over an MPLS Packet Switched Network, RFC 6391, November 2011.
mpw kernel interface first appeared in
mpw driver was written by