Add pair(4), a vether-based virtual Ethernet driver to interconnect

rdomains and bridges on the local system.  This can be used to route
through local rdomains, to create L2 devices (like trunks) between
them, and many other things.

Discussed with many, with input from mpi@
OK sthen@ phessler@ yasuoka@ mikeb@

1 files changed, 28 insertions, 1 deletions

diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 2e4897d038e..c2cab164b11 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ifconfig.8,v 1.259 2015/10/24 08:42:57 jmc Exp $
+.\"	$OpenBSD: ifconfig.8,v 1.260 2015/10/24 10:52:05 reyk Exp $
 .\"	$NetBSD: ifconfig.8,v 1.11 1996/01/04 21:27:29 pk Exp $
 .\"     $FreeBSD: ifconfig.8,v 1.16 1998/02/01 07:03:29 steve Exp $
 .\"
@@ -1270,6 +1270,33 @@ The
 is an IPv4 address that will be used to find the nexthop in the MPLS
 network.
 .El
+.\" PAIR
+.Sh PAIR
+.nr nS 1
+.Bk -words
+.Nm ifconfig
+.Ar pair-interface
+.Op Oo Fl Oc Ns Cm patch Ar interface
+.Ek
+.nr nS 0
+.Pp
+The following options are available for a
+.Xr pair 4
+interface:
+.Bl -tag -width Ds
+.It Cm patch Ar interface
+Connect the interface with a second
+.Xr pair 4
+interface.
+Any outgoing packets from the first
+.Ar pair-interface
+will be received by the second
+.Ar interface
+and vice versa.
+This link allows to interconnect two routing domains locally.
+.It Fl patch
+If configured, disconnect the interface pair.
+.El
 .\" PFLOW
 .Sh PFLOW
 .nr nS 1