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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" From: @(#)lo.4 8.1 (Berkeley) 6/5/93 33.\" $FreeBSD$ 34.\" 35.Dd May 25, 2002 36.Dt DISC 4 37.Os 38.Sh NAME 39.Nm disc 40.Nd software discard network interface 41.Sh SYNOPSIS 42.Cd "device disc" 43.Sh DESCRIPTION 44The 45.Nm 46interface is a software discard mechanism which may be 47used for performance analysis and/or software testing. 48As with other network interfaces, the discard interface must have 49network addresses assigned for each address family with which it is to be used. 50These addresses 51may be set or changed with the 52.Dv SIOCSIFADDR 53.Xr ioctl 2 . 54.Pp 55Each 56.Nm 57interface is created at runtime using interface cloning. 58This is 59most easily done with the 60.Xr ifconfig 8 61.Cm create 62command or using the 63.Va cloned_interfaces 64variable in 65.Xr rc.conf 5 . 66.Sh SEE ALSO 67.Xr inet 4 , 68.Xr intro 4 69.\" .Xr ns 4 70.Sh HISTORY 71The 72.Nm 73device appears to have been derived from the 74.Xr lo 4 75device around the time of 76.Bx 4.4 . 77This manpage was adapted from 78.Xr lo 4 79and first appeared in 80.Fx 5.0 . 81