1*8aa0c375Smillert.\" $OpenBSD: tcpdrop.8,v 1.14 2023/02/06 18:14:10 millert Exp $ 24b9445ffSmarkus.\" 34b9445ffSmarkus.\" Copyright (c) 2004 Markus Friedl <markus@openbsd.org> 44b9445ffSmarkus.\" 54b9445ffSmarkus.\" Permission to use, copy, modify, and distribute this software for any 64b9445ffSmarkus.\" purpose with or without fee is hereby granted, provided that the above 74b9445ffSmarkus.\" copyright notice and this permission notice appear in all copies. 84b9445ffSmarkus.\" 94b9445ffSmarkus.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 104b9445ffSmarkus.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 114b9445ffSmarkus.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 124b9445ffSmarkus.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 134b9445ffSmarkus.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 144b9445ffSmarkus.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 154b9445ffSmarkus.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 164b9445ffSmarkus.\" 17*8aa0c375Smillert.Dd $Mdocdate: February 6 2023 $ 184b9445ffSmarkus.Dt TCPDROP 8 194b9445ffSmarkus.Os 204b9445ffSmarkus.Sh NAME 214b9445ffSmarkus.Nm tcpdrop 224b9445ffSmarkus.Nd drop a TCP connection 234b9445ffSmarkus.Sh SYNOPSIS 244b9445ffSmarkus.Nm tcpdrop 254150247bSderaadt.Ar local-addr 264150247bSderaadt.Ar local-port 274150247bSderaadt.Ar remote-addr 284150247bSderaadt.Ar remote-port 294b9445ffSmarkus.Sh DESCRIPTION 304b9445ffSmarkusThe 314b9445ffSmarkus.Nm 324b9445ffSmarkuscommand drops the TCP connection specified by the local address 334150247bSderaadt.Ar local-addr , 344b9445ffSmarkusport 354150247bSderaadt.Ar local-port 364b9445ffSmarkusand the foreign address 374150247bSderaadt.Ar remote-addr , 384b9445ffSmarkusport 394150247bSderaadt.Ar remote-port . 400f340300SottoAddresses and ports can be specified by name or numeric value. 41*8aa0c375Smillert.Pp 42*8aa0c375SmillertTo simplify dropping TCP connections using the output of 43*8aa0c375Smillert.Xr fstat 1 44*8aa0c375Smillertand 45*8aa0c375Smillert.Xr netstat 1 , 46*8aa0c375Smillert.Nm 47*8aa0c375Smillertalso supports a two-argument form where the address and port are 48*8aa0c375Smillertseparated by a colon 49*8aa0c375Smillert.Pq Sq \&: 50*8aa0c375Smillertor dot 51*8aa0c375Smillert.Pq Sq \&. 52*8aa0c375Smillertcharacter. 530945da04Sjmc.Sh EXAMPLES 540945da04SjmcIf a connection to 551b1da000Sjmc.Xr httpd 8 560945da04Sjmcis causing congestion on a network link, one can drop the TCP session 570f340300Sottoin charge: 580945da04Sjmc.Bd -literal -offset indent 591b1da000Sjmc$ fstat | grep 'httpd.*internet.*<--' 601b1da000Sjmcwww httpd 21307 3* internet stream tcp \e 611b1da000Sjmc 0xd1007ca8 192.168.5.41:80 <-- 192.168.5.1:26747 6248132b45Spb.Ed 6348132b45Spb.Pp 6418231cbeSderaadtEither of the following commands will drop the connection: 650945da04Sjmc.Bd -literal -offset indent 6648132b45Spb# tcpdrop 192.168.5.41 80 192.168.5.1 26747 6718231cbeSderaadt 6818231cbeSderaadt# tcpdrop 192.168.5.41:80 192.168.5.1:26747 69*8aa0c375Smillert 70*8aa0c375Smillert# tcpdrop 192.168.5.41.80 192.168.5.1.26747 7148132b45Spb.Ed 724b9445ffSmarkus.Sh SEE ALSO 7348132b45Spb.Xr fstat 1 , 744b9445ffSmarkus.Xr netstat 1 752280d6e5Sxsa.Sh HISTORY 762280d6e5SxsaThe 772280d6e5Sxsa.Nm 782280d6e5Sxsaprogram first appeared in 792280d6e5Sxsa.Ox 3.6 . 802280d6e5Sxsa.Sh AUTHORS 812280d6e5Sxsa.An -nosplit 822280d6e5SxsaThe 832280d6e5Sxsa.Nm 842280d6e5Sxsaprogram was written by 8544e68d47Sschwarze.An Markus Friedl Aq Mt markus@openbsd.org . 86