====== Internet Gate's Firewall ======

The Internet Gate contains a powerful firewall protecting your computers from the Internet.

===== Firewall Overview =====

=== What is a firewall? ===

The firewall works like a barrier that keeps destructive forces away from your computers. It guarantees that only allowed traffic passes in and out between the two networks. [[wp>Firewall_(computing)|Firewall]]

=== How does a firewall protect? ===

The Internet Gate's firewall examines all communication passing through and maps it with its defined security rules. The rules based on the senders address, receiving address, and which protocol and ports used.

Even the way the communication is carried out, the protocol, is examined, which prevents that badly implemented applications on secure servers goes down if they receive unexpected data.

===== Firewall Technologies =====

The firewall uses different methods to examine and control the data traffic passing through in and out of the local network.

=== Packet Filtering ===

Packets (small chunks of data) are analysed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.

=== Stateful Inspection ===

A method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information. Information travelling from inside the firewall to the outside is monitored for specific defining characteristics, and then incoming information is compared to these characteristics. If the comparison yields a reasonable match, the information is allowed through. Otherwise it is discarded. The Internet Gate's firewall implement stateful inspection using [[firewall:flows|flows]].

=== Proxy ===

Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa. [[wp>Proxy_server|Proxy]]

===== Security Profiles =====

The Internet Gate uses [[firewall:security profiles]] to store its security settings. The security profiles provide an easy way for users, without previous knowledge about network security, to administrate the firewall.

The predefined security profiles are prepared with support for the most commonly used applications, games and services. The default settings of the security profiles will be sufficient for most users. By changing between the profiles, you control what traffic is allowed to pass.

You toggle between the security profiles with the **ALT** key located on the Internet Gate front panel. You can also select security profile from the Internet Gate [[web GUI:main menu|web interface]].

===== Edit Security Profiles =====

To configure security profiles open the [[web GUI:security profile|Security]] webpage from the [[web GUI:main menu]].

Advanced users can use a powerful firewall rule [[firewall:syntax]] to enter their [[firewall:tutorial|own rules]].