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Firewall

Friday, February 1st, 2008

What is a Firewall?

A Firewall is a network security device that inspects network traffic and blocks or permits access based on a set of rules. Firewalls can be implemented as either software packages or hardware appliances. Much like a firewall that is constructed around a building or an engine to prevent the spread of heat and fire, a computer firewall establishes a perimeter around computer systems in order to protect them from dangerous or unauthorized elements.

A computer system that is connected to the Internet without firewall protection is basically welcoming cyber criminals with open arms. But with this kind of uninhibited access, an attacker can cause a lot of damage. By downloading a keystroke logger, Trojan or spyware onto a victims system, they have the ability to remotely monitor sensitive information that is on or passing through the system. They typically target information that they can steal and resell, such as credit card or social security numbers, but really they are looking for anything beneficial, including username and password combinations.

What Does a Firewall Do?

In order to slam the door on unwanted intruders, firewalls must monitor every point of entry, or port. Ports are used to direct incoming data to a specific application. Different applications use different ports to transmit data, in order to prevent confusing one application’s data for another’s. As such, legitimate traffic follows a predictable pathway. Firewalls prevent data from entering a system from anywhere but these specific ports, and also analyzes the data coming in to ensure that it’s not a threat in disguise.

Two Way Firewall

Two-way firewalls have emerged within recent years in order to protect sensitive data from being transmitted outside of a secure network. One-way firewalls only inspect and restrict data coming from the Internet into a computer system, whereas two-way firewalls prevent unauthorized inbound, as well as outbound connections. Firewalls that protect the flow of network traffic in both directions provide the greatest protection, and if setup correctly, can prevent, as well as notify you of, unauthorized connections.

Integrated Firewall Protection

Due to increased security threats to Internet users, many leading internet security companies now offer firewall protection that works hand-in-hand with essential online protection utilities, such as anti virus and anti-spyware. This integrated protection provides muliple layers of defense from hackers, viruses, spyware, Trojans, keyloggers, and other malicious threats. Effective integrated firewall and anti malware protection is offered by: McAfee, Norton by Symantec, Panda Software, and Grisoft’s AVG.