fwknop-server software package provides FireWall KNock OPerator server side - C version, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install fwknop-server
fwknop-server is installed in your system.
Make ensure the fwknop-server package were installed using the commands given below,
$ sudo dpkg-query -l | grep fwknop-server *
You will get with fwknop-server package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Administration Utilities |
| Package | fwknop-server |
| Version | 2.0.0rc2-2+deb7u2 |
| Description | FireWall KNock OPerator server side - C version |
| Sub Section | Admin |