knock - port-knock client
knock [options] <host> <port[:proto]>
[port[:proto]] ...
knock is a port-knock client. It sends TCP/UDP
packets to each specified port on host, creating a special
knock sequence on the listening server (see the knockd manpage for
more info on this).
- -u, --udp
- Make all port hits use UDP (default is TCP). If you want each port to use
a different protocol (TCP or UDP), then you can specify the protocol on a
per-port basis. See the example below.
- -d <t>, --delay
<t>
- Wait <t> milliseconds between each port hit. This can be used in
situations where a router mistakes your stream of SYN packets as a port
scan and blocks them. If the packet rate is slowed with --delay, then the
router should let the packets through.
- -4, --ipv4 <version>
- Force usage of IPv4.
- -6, --ipv6 <version>
- Force usage of IPv6.
- -v, --verbose
- Output verbose status messages.
- -V, --version
- Display the version.
- -h, --help
- Syntax help.
knock myserver.example.com 123:tcp 456:udp 789:tcp
knock -u myserver.example.com 8284 4721 18592 42912
knockd is the accompanying port-knock server.
Judd Vinet <jvinet@zeroflux.org>