Hello and welcome in this course will talk about the Linux firewall as a firewall is a network security
system that monitors and controls incoming and outgoing network traffic based on predetermined security
rules.
A firewall typically establishes a barrier between a trusted internal network and an trusted external
network such as the Internet.
Firewalls are an important tool of it can be configured to protect your servers and infrastructure.
The final solution for Lennox is called net filter, net filter is a software firewall, a packet filtering
framework inside the Linux kernel.
It enables packet filtering network and port address, translation, port forwarding and packet alteration,
which is the process of intentionally altering data and IP packet headers before or after the routing
process.
Net filter is the professional and the mostly used solution for building firewalls in Linux operating
systems.
The net filter framework is controlled by the IP tables command IP tables is a tool that belongs to
the user space used to configure net filter.
It is said that net filter belongs to the cable space and IP table belongs to the user space.
Most of the time, net filtering and IP tables are often combined into a single expression net filter
IP tables.
In this course, we want to make a very clear distinction between IP tables, internet filter and simply
refer to the entire thing as IP tables.
Then you should know that every Linux distribution uses net filter and IP tables and there is nothing
extra, no extra software that should be installed.
IP tables is already there.
You should also know that only you can configure the net filter framework or use the IP tables comment.
This was a very short introduction to net filter and IP tables and in the next lectures will dive deep
into almost every IP table option available.