WEBVTT

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Hello and welcome in this course will talk about the Linux firewall as a firewall is a network security

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system that monitors and controls incoming and outgoing network traffic based on predetermined security

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rules.

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A firewall typically establishes a barrier between a trusted internal network and an trusted external

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network such as the Internet.

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Firewalls are an important tool of it can be configured to protect your servers and infrastructure.

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The final solution for Lennox is called net filter, net filter is a software firewall, a packet filtering

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framework inside the Linux kernel.

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It enables packet filtering network and port address, translation, port forwarding and packet alteration,

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which is the process of intentionally altering data and IP packet headers before or after the routing

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process.

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Net filter is the professional and the mostly used solution for building firewalls in Linux operating

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systems.

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The net filter framework is controlled by the IP tables command IP tables is a tool that belongs to

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the user space used to configure net filter.

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It is said that net filter belongs to the cable space and IP table belongs to the user space.

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Most of the time, net filtering and IP tables are often combined into a single expression net filter

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IP tables.

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In this course, we want to make a very clear distinction between IP tables, internet filter and simply

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refer to the entire thing as IP tables.

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Then you should know that every Linux distribution uses net filter and IP tables and there is nothing

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extra, no extra software that should be installed.

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IP tables is already there.

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You should also know that only you can configure the net filter framework or use the IP tables comment.

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This was a very short introduction to net filter and IP tables and in the next lectures will dive deep

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into almost every IP table option available.