. What is a Firewall and why is it used?

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Posts: 314
Joined: Tue Aug 06, 2019 2:07 pm

Sat Aug 10, 2019 4:46 pm

A Firewall is a network security system set on the boundaries of the system/network that monitors and controls network traffic. Firewalls are mainly used to protect the system/network from viruses, worms, malware, etc. Firewalls can also be to prevent remote access and content filtering.
Posts: 327
Joined: Wed Jan 29, 2020 2:36 pm

Wed Jan 27, 2021 1:03 pm

A firewall, at its most basic level, is a router on the network, which certain traffic must pass through to get to its destination. It blocks all traffic except those data packets that match the rules coded into the router. For instance, a specific IP address on one side of the firewall to another specific IP address on the other side of the firewall, communicating through a specific port using a specific protocol.

In this way, unwanted traffic / unexpected traffic is prevented from getting to the network (or devices on the network) behind the firewall.

Where the firewall is placed, how it is configured, its potential processing speed, and the rules on it all impact on its effectiveness.

The most basic of firewalls can be a rule set on a router (e.g. Cisco, HP) or could be a hardened Linux PC. Enterprise level firewalls can be dedicated and focus on processing speed, or multi-functional such as a Unified Threat Management (UTM) device - consolidating multiple networking security functions (not just a firewall) into one purpose built appliance.
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