fwknop-server software package provides FireWall KNock OPerator server side, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) 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 | Ubuntu 12 04 lts precise pangolin |
| Section | Administration Utilities |
| Package | fwknop-server |
| Version | 1.9.12-3 |
| Description | FireWall KNock OPerator server side |
| Sub Section | Admin |