wok view knock/description.txt @ rev 25503
f3: include extra programs
| author | Hans-G?nter Theisgen |
|---|---|
| date | Fri Jan 27 10:37:43 2023 +0100 (15 months ago) |
| parents | |
| children |
line source
1 Knockd is a port-knock server.
2 It listens to all traffic on an ethernet (or PPP) interface, looking
3 for special "knock" sequences of port-hits.
4 A client makes these port-hits by sending a TCP (or UDP) packet to a
5 port on the server. This port need not be open -- since knockd listens
6 at the link-layer level, it sees all traffic even if it's destined for
7 a closed port.
8 When the server detects a specific sequence of port-hits, it runs a
9 command defined in its configuration file. This can be used to open up
10 holes in a firewall for quick access.