ipkungfu software package provides iptables-based Linux firewall, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install ipkungfu
ipkungfu is installed in your system.
Make ensure the ipkungfu package were installed using the commands given below,
$ sudo dpkg-query -l | grep ipkungfu *
You will get with ipkungfu package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Network |
| Package | ipkungfu |
| Version | 0.6.1-6.1 |
| Description | iptables-based Linux firewall |
| Sub Section | Net |