1.\" $OpenBSD: tcpdrop.8,v 1.13 2014/08/28 08:22:42 jmc Exp $ 2.\" 3.\" Copyright (c) 2004 Markus Friedl <markus@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: August 28 2014 $ 18.Dt TCPDROP 8 19.Os 20.Sh NAME 21.Nm tcpdrop 22.Nd drop a TCP connection 23.Sh SYNOPSIS 24.Nm tcpdrop 25.Ar local-addr 26.Ar local-port 27.Ar remote-addr 28.Ar remote-port 29.Nm tcpdrop 30.Ar local-addr : Ns Ar local-port 31.Ar remote-addr : Ns Ar remote-port 32.Sh DESCRIPTION 33The 34.Nm 35command drops the TCP connection specified by the local address 36.Ar local-addr , 37port 38.Ar local-port 39and the foreign address 40.Ar remote-addr , 41port 42.Ar remote-port . 43Addresses and ports can be specified by name or numeric value. 44.Sh EXAMPLES 45If a connection to 46.Xr httpd 8 47is causing congestion on a network link, one can drop the TCP session 48in charge: 49.Bd -literal -offset indent 50$ fstat | grep 'httpd.*internet.*<--' 51www httpd 21307 3* internet stream tcp \e 52 0xd1007ca8 192.168.5.41:80 <-- 192.168.5.1:26747 53.Ed 54.Pp 55Either of the following commands will drop the connection: 56.Bd -literal -offset indent 57# tcpdrop 192.168.5.41 80 192.168.5.1 26747 58 59# tcpdrop 192.168.5.41:80 192.168.5.1:26747 60.Ed 61.Sh SEE ALSO 62.Xr fstat 1 , 63.Xr netstat 1 64.Sh HISTORY 65The 66.Nm 67program first appeared in 68.Ox 3.6 . 69.Sh AUTHORS 70.An -nosplit 71The 72.Nm 73program was written by 74.An Markus Friedl Aq Mt markus@openbsd.org . 75