1.\" $NetBSD: tcpdrop.8,v 1.1 2007/06/25 23:34:52 christos Exp $ 2.\" 3.\" Copyright (c) 1989, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Herb Hasler and Rick Macklem at The University of Guelph. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" $OpenBSD: tcpdrop.8,v 1.6 2006/01/03 14:52:17 jmc Exp $ 34.\" 35.\" Copyright (c) 2004 Markus Friedl <markus@openbsd.org> 36.\" 37.\" Permission to use, copy, modify, and distribute this software for any 38.\" purpose with or without fee is hereby granted, provided that the above 39.\" copyright notice and this permission notice appear in all copies. 40.\" 41.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 42.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 43.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 44.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 45.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 46.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 47.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 48.\" 49.Dd June 23, 2007 50.Dt TCPDROP 8 51.Os 52.Sh NAME 53.Nm tcpdrop 54.Nd drop a TCP connection 55.Sh SYNOPSIS 56.Nm tcpdrop 57.Ar laddr 58.Ar lport 59.Ar faddr 60.Ar fport 61.Sh DESCRIPTION 62The 63.Nm 64command drops the TCP connection specified by the local address 65.Ar laddr , 66port 67.Ar lport 68and the foreign address 69.Ar faddr , 70port 71.Ar fport . 72Addresses and ports can be specified by name or numeric value. 73.Sh EXAMPLES 74If a connection to 75.Xr httpd 8 76is causing congestion on a network link, one can drop the TCP session 77in charge: 78.Bd -literal -offset indent 79$ fstat | grep 'httpd.*internet.*\*(Lt--' 80www httpd 21307 3* internet stream tcp \e 81 0xd1007ca8 192.168.5.41:80 \*(Lt-- 192.168.5.1:26747 82.Ed 83.Pp 84The following command will drop the connection: 85.Bd -literal -offset indent 86# tcpdrop 192.168.5.41 80 192.168.5.1 26747 87.Ed 88.Sh SEE ALSO 89.Xr fstat 1 , 90.Xr netstat 1 91