1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" From: @(#)lo.4 8.1 (Berkeley) 6/5/93 29.\" $FreeBSD$ 30.\" 31.Dd May 25, 2002 32.Dt DISC 4 33.Os 34.Sh NAME 35.Nm disc 36.Nd software discard network interface 37.Sh SYNOPSIS 38.Cd "device disc" 39.Sh DESCRIPTION 40The 41.Nm 42interface is a software discard mechanism which may be 43used for performance analysis and/or software testing. 44As with other network interfaces, the discard interface must have 45network addresses assigned for each address family with which it is to be used. 46These addresses 47may be set or changed with the 48.Dv SIOCSIFADDR 49.Xr ioctl 2 . 50.Pp 51Each 52.Nm 53interface is created at runtime using interface cloning. 54This is 55most easily done with the 56.Xr ifconfig 8 57.Cm create 58command or using the 59.Va cloned_interfaces 60variable in 61.Xr rc.conf 5 . 62.Sh SEE ALSO 63.Xr inet 4 , 64.Xr intro 4 65.\" .Xr ns 4 66.Sh HISTORY 67The 68.Nm 69device appears to have been derived from the 70.Xr lo 4 71device around the time of 72.Bx 4.4 . 73This manpage was adapted from 74.Xr lo 4 75and first appeared in 76.Fx 5.0 . 77