Network Security: Firewalls

Today’s organizations face an increasing number of malicious threats across their networks (LAN, WAN, and at endpoints). Fast-paced business world need unified, multifaceted protection from these threats, backed by strong performance and complete reliability. Protecting them all can result in security sprawl, an ever-increasing set of product that is hard to manage and result in inconsistent security.
A firewall is a protective system that lies, in essence, between your computer network and the Internet. When used correctly, a firewall prevents unauthorized use and access to your network. The job of a firewall is to carefully analyze data entering and exiting the network based on your configuration. It ignores information that comes from an unsecured, unknown or suspicious location. A firewall plays an important role on any network as it provides a protective barrier against most forms of attack coming from the outside world.

Firewalls can be either hardware or software. The ideal firewall configuration will consist of both. In addition to limiting access to you computer and network, a firewall is also useful for allowing remote access to a private network through secure authentication certificates and logins.

In the past, a connected enterprise needed a complex set of tools, systems, and personnel for access control, authentication, virtual private networking, network management, and security analysis. These costly systems were difficult to integrate and not easy to update.
Today, the Hardware firewall systems (e.g. Watch Guard, Check Point etc) deliver a complete network security solution to meet these modern security challenges:

# Keeping network defenses current
# Protecting every office connected to the internet
# Encrypting communications to remote offices and traveling users
# Managing the security system from a single site

A hardware firewall uses packet filtering to examine the header of a packet to determine its source and destination. This information is compared to a set of predefined or user-created rules that determine whether the packet is to be forwarded or dropped. Hardware firewalls are important because they provide a strong degree of protection from most forms of attack coming from the outside world. Additionally, in most cases, they can be effective with little or no configuration, and they can protect every machine on a local network.

A hardware firewall in a typical broadband router employs a technique called packet filtering, which examines the header of a packet to determine its source and destination addresses. A more advanced technique called Stateful Packet Inspection (SPI) looks at additional characteristics such as a packet's actual origin and whether incoming traffic is a response to existing outgoing connections, like a request for a Web page.

To most hardware firewalls, the traffic generated by such programs would appear legitimate since it originated inside your network and would most likely be let through. This malevolent traffic might be blocked if the hardware firewall was configured to block outgoing traffic on the specific Transmission Control Protocol/Internet Protocol (TCP/IP) port(s) the program was using, but given that there are over 65,000 possible ports and there's no way to know which ports a program of this nature might use, the odds of the right ones being blocked are slim.

When properly configured and administered, the hardware firewall system reliably defends any network against external threats.