1knockd(1)                                                            knockd(1)
2
3
4

NAME

6       knock - port-knock client
7

SYNOPSIS

9       knock [options] <host> <port[:proto]> [port[:proto]] ...
10

DESCRIPTION

12       knock  is a port-knock client.  It sends TCP/UDP packets to each speci‐
13       fied port on host, creating a special knock sequence on  the  listening
14       server (see the knockd manpage for more info on this).
15

OPTIONS

17       -u, --udp
18              Make  all  port hits use UDP (default is TCP).  If you want each
19              port to use a different protocol (TCP  or  UDP),  then  you  can
20              specify  the  protocol on a per-port basis.  See the example be‐
21              low.
22
23       -d <t>, --delay <t>
24              Wait <t> milliseconds between each port hit.  This can  be  used
25              in situations where a router mistakes your stream of SYN packets
26              as a port scan and blocks them.  If the packet  rate  is  slowed
27              with --delay, then the router should let the packets through.
28
29       -4, --ipv4 <version>
30              Force usage of IPv4.
31
32       -6, --ipv6 <version>
33              Force usage of IPv6.
34
35       -v, --verbose
36              Output verbose status messages.
37
38       -V, --version
39              Display the version.
40
41       -h, --help
42              Syntax help.
43

EXAMPLES

45       knock myserver.example.com 123:tcp 456:udp 789:tcp
46       knock -u myserver.example.com 8284 4721 18592 42912
47

SEE ALSO

49       knockd is the accompanying port-knock server.
50

AUTHOR

52       Judd Vinet <jvinet@zeroflux.org>
53
54
55
56knockd 0.8                      April 22, 2021                       knockd(1)