What Do Firewalls Do?

A firewall is a network security device that ensures that all communications attempting to cross it meet an organization's security policy. Firewalls track and control communications, deciding whether to allow, reject or encrypt communications. While most firewalls provide effective access control, many are not designed to detect and thwart attacks at the application level. In order to address the increasing threat from application-driven attacks, firewalls must provide comprehensive security on multiple-levels. These levels of security should protect against both network and application attacks, while providing robust access control to IT resources.

The firewall module provides protection from common attacks; there are several common types of attacks that hackers employ to gain access or damage a network. These attacks are easily defeated by the firewall:

Hacking (or cracking)
This is what happens when someone who breaks into someone else's computer system, bypasses passwords or licenses in computer programs; or in other ways intentionally breaches computer security. The end result is whatever is on the computer can be viewed and sensitive data stolen without anyone knowing. Sometimes, tiny programs are 'planted' on the computer that are designed to watch out for, seize and then transmit to another computer, specific types of data.


IP Spoofing
A technique where an attacker attempts to gain unauthorized access through a false source address to make it appear as though communications have originated in a part of the network with higher access privileges. For example, a packet originating on the Internet may be masquerading as a local packet with the source IP address of an internal host. The firewall can protect against IP spoofing attacks by limiting network access based on the gateway interface from which data is being received.

Denial of Service Attack
There are many types of denial of service (DoS) attacks. These typically involve "bombarding" a machine with erroneous Internet packets, thereby overloading it and denying access to certain Internet services.

 
ADDITIONAL RESOURCES HEADLINE: Serious Business About Your Business

1. How Do Firewalls Work?

2. WebImmunity - Business Protection

3. Major Online Security Threats