knock - A Port-Knocking Client

Distribution: openSUSE 13.2
Repository: openSUSE Network Utilities all
Package name: knock
Package version: 0.7
Package release: 300.2
Package architecture: i586
Package type: rpm
Installed size: 10.38 KB
Download size: 8.27 KB
Official Mirror:
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.



  • knock = 0.7-300.2
  • knock(x86-32) = 0.7-300.2


    Binary package: knock-0.7-300.2.i586.rpm
    Source package: knock-0.7-300.2.src.rpm

    Install Howto

    1. Add the openSUSE Network Utilities repository:
      # zypper addrepo opensuse-network-utilities
    2. Install knock rpm package:
      # zypper install knock


    • /usr/bin/knock
    • /usr/share/man/man1/knock.1.gz


    2015-12-01 - - Update to version 0.7 * Document the 'target' configuration directive. * Merging OS-specific networking code to reduce LOCs and the sea of #ifdefs. * Added 50ms timeout to pcap_open_live() to reduce CPU usage on network-heavy hosts. Pcap recommends we not use zero. - Changes from version 0.6 * Cleanup: Don't null-check before free * Cleanup: Consolidate flag-check logic * Accept single-knock sequences * Introduce a 'target' configuration directive, enabling knockd to react to connect attempts to a target host. Useful in cases where knockd is on a router and you want to send a target a wakeup packet. - Add systemd support for openSUSE > 12.1 - Update knock-include.patch > knock-0.5-include.patch - Remove obsolete AUTHORS section - Use download Url as source - Perform a spec-cleaner

    2009-06-15 - - Add knock-0.5-include.patch to fix build failure.

    2007-07-26 - - changed libpcap to libpcap-devel in BuildRequires

    2006-11-14 - - fix bug #220355 (iptables call is wrong)

    2006-10-04 - - fix bug in iptables call

    2006-09-25 - - fix iptables call in config

    2006-09-22 - - fix sysconfig file

    2006-01-25 - - converted neededforbuild to BuildRequires

    2005-06-30 - - Initial Package, Version 0.5