1 .\" $OpenBSD: tcpdrop.8,v 1.5 2004/05/24 13:57:31 jmc Exp $
3 .\" Copyright (c) 2009 Juli Mallett <jmallett@FreeBSD.org>
4 .\" Copyright (c) 2004 Markus Friedl <markus@openbsd.org>
6 .\" Permission to use, copy, modify, and distribute this software for any
7 .\" purpose with or without fee is hereby granted, provided that the above
8 .\" copyright notice and this permission notice appear in all copies.
10 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 .Dd September 12, 2017
25 .Nd drop TCP connections
48 command may be used to drop TCP connections from the command line.
54 will attempt to drop all TCP connections.
60 will attempt to drop all connections using the TCP stack
67 will attempt to drop all TCP connections being in the state
83 flag may be given in addition to the
88 options to list the tcpdrop invocation to drop all corresponding TCP
89 connections one at a time.
96 options are specified then only the connection between the given local
101 and the foreign address
102 .Ar foreign-address ,
107 Addresses and ports may be specified by name or numeric value.
108 Both IPv4 and IPv6 address formats are supported.
110 The addresses and ports may be separated by periods or colons
117 is causing congestion on a network link, one can drop the TCP session
119 .Bd -literal -offset indent
120 # sockstat -c | grep httpd
121 www httpd 16525 3 tcp4 \e
122 192.168.5.41:80 192.168.5.1:26747
125 The following command will drop the connection:
126 .Bd -literal -offset indent
127 # tcpdrop 192.168.5.41 80 192.168.5.1 26747
130 The following command will drop all connections but those to or from
131 port 22, the port used by
133 .Bd -literal -offset indent
134 # tcpdrop -l -a | grep -vw 22 | sh
137 The following command will drop all connections using the TCP stack
139 .Bd -literal -offset indent
143 To drop all TCP connections in the LAST_ACK state use:
144 .Bd -literal -offset indent
145 # tcpdrop -s LAST_ACK
148 To drop all TCP connections using the TCP stack fastack and being in the
150 .Bd -literal -offset indent
151 # tcpdrop -S fastack -s LAST_ACK
157 .An Markus Friedl Aq Mt markus@openbsd.org
158 .An Juli Mallett Aq Mt jmallett@FreeBSD.org