knock

A Port-Knocking Client

The server part (package knockd) listens to all traffic on an ethernet (or PPP) interface, looking for special "knock" sequences of port hits. This client makes these port hits by sending a TCP (or UDP) packet to a port on the server. This port does not need to be open. Since knockd listens at the link-layer level, it sees all traffic even if it is destined for a closed port. When the server detects a specific sequence of port hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access.

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openSUSE Tumbleweed

openSUSE Leap 15.2

SUSE SLE-15-SP2

SUSE SLE-15-SP1

SUSE SLE-12-SP5

SUSE SLE-11 SP 4

Unsupported distributions

The following distributions are not officially supported. Use these packages at your own risk.