.\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" From: @(#)lo.4 8.1 (Berkeley) 6/5/93 .\" $FreeBSD: src/share/man/man4/disc.4,v 1.2.4.1 2003/04/15 18:24:28 trhodes Exp $ .\" $DragonFly: src/share/man/man4/disc.4,v 1.2 2003/06/17 04:36:58 dillon Exp $ .\" .Dd May 25, 2002 .Dt DISC 4 .Os .Sh NAME .Nm disc .Nd software discard network interface .Sh SYNOPSIS .Cd "pseudo-device disc" .Sh DESCRIPTION The .Nm interface is a software discard mechanism which may be used for performance analysis and/or software testing. As with other network interfaces, the discard interface must have network addresses assigned for each address family with which it is to be used. These addresses may be set or changed with the .Dv SIOCSIFADDR .Xr ioctl 2 . .Pp Each .Nm interface is created at runtime using interface cloning. This is most easily done with the .Xr ifconfig 8 .Cm create command or using the .Va cloned_interfaces variable in .Xr rc.conf 5 . .Sh SEE ALSO .Xr inet 4 , .Xr intro 4 .\" .Xr ns 4 .Sh HISTORY The .Nm device appears to have been derived from the .Xr lo 4 device around the time of .Bx 4.4 . This manpage was adapted from .Xr lo 4 and first appeared in .Fx 5.0 .