.\"	$OpenBSD: trunk.4,v 1.3 2005/05/31 20:57:49 jmc Exp $
.\"
.\" Copyright (c) 2005 Reyk Floeter <reyk@vantronix.net>
.\"
.\" 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.
.\"
.\" 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
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd May 5, 2005
.Dt TRUNK 4
.Os
.Sh NAME
.Nm trunk
.Nd link aggregation and link failover interface
.Sh SYNOPSIS
.Cd "pseudo-device trunk" Op Ar count
.Sh DESCRIPTION
The
.Nm
interface allows aggregation of multiple network interfaces as one virtual
.Nm
interface.
.Pp
A
.Nm
interface can be created using the
.Ic ifconfig trunk Ns Ar N Ic create
command.
It can use different link aggregation protocols specified
using the
.Ic trunkproto Ar proto
option.
Child interfaces can be added using the
.Ic trunkport Ar child-iface
option and removed using the
.Ic -trunkport Ar child-iface
option.
.Pp
The driver currently supports the trunk protocols
.Ic roundrobin
.Oo
.Ic default
.Oc
and
.Ic none
for link aggregation and link failover.
.Pp
The configuration can be done at runtime or by setting up a
.Xr hostname.if 5
configuration file for
.Xr netstart 8 .
.Sh SEE ALSO
.Xr inet 4 ,
.Xr hostname.if 5 ,
.Xr ifconfig 8 ,
.Xr netstart 8
.Sh HISTORY
The
.Nm
device appeared in
.Ox 3.8 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Reyk Floeter Aq reyk@openbsd.org .
.Sh CAVEATS
Currently only the roundrobin trunk protocol is supported.