What is a Firewall?
A firewall is network security technology positioned between two different networks, usually between an organization’s internal, trusted network and the Internet.

A firewall ensures that all communications attempting to cross from one network to the other meet an organization’s security policy. Firewalls track and control communications, deciding whether to allow, reject or encrypt communications. In addition to protecting trusted networks from the Internet, firewalls are increasingly being deployed to protect sensitive portions of local area networks and individual PCs.

Why does an organization need a Firewall?
Organizations around the world are embracing the Internet and Internet technologies to forge new and profitable business relationships. Firewalls help organizations balance the openness of the Internet with the need to protect the privacy and integrity of sensitive business communications.

How do Firewalls work?
Historically, three different technologies have been used to implement firewalls: Packet Filters, Application-Layer Gateways and Stateful Inspection.

Packet Filters
Packet filters, usually implemented on routers, filter traffic based on packet content, such as IP addresses. They examine a packet at the network layer and are application independent, which allows them to deliver good performance and scalability. They are the least secure type of firewall, however. The reason is that they are not application aware—that is, they cannot understand the context of a given communication, making them easier for hackers to break.

Application-Layer Gateways
Application gateways improve on security by examining all application layers, bringing context information into the decision process. However, they do this by breaking the client/server model. Every client/server communication requires two connections: one from the client to the firewall (which acts as a "proxy" for the desired server) and one from the firewall to the (actual) server. In addition, every application requires a new proxy, making scalability and support for new applications a problem.

Stateful Inspection
Stateful Inspection provides the highest level of security possible and overcomes the limitations of the previous two approaches by providing full application-layer awareness without breaking the client/server model. Stateful Inspection extracts the state-related information required for security decisions from all application layers and maintains this information in dynamic state tables for evaluating subsequent connection attempts. This provides a solution that is highly secure and offers maximum performance, scalability, and extensibility. Check Point FireWall-1 is based upon Stateful Inspection, which has become the de facto standard for firewalls.

What is a Virtual Private Network (VPN)?
Today’s enterprise networks reflect the new world of e-business, extending across the Internet to connect customers, partners, and remote users. Virtual private networks (VPNs) enable these e-business connections by allowing organizations to leverage the cost savings and flexibility of the Internet while protecting sensitive business information.  Check Point Software Technologies’ Secure Virtual Network (SVN) architecture provides security for this new world of e-business so that corporations can share critical information and resources with partners, suppliers, and others who must be closely linked. SVN extends security to networks, systems, applications and users and across intranets, extranets and the Internet.

What is High Availability?
Businesses that rely on firewalls and VPNs to secure their mission critical data can lose thousands of dollars if they lose connectivity. These businesses must guarantee uninterrupted access to network resources. High availability products deliver seamless fail-over for VPNs and firewalls. In the event that a primary gateway fails, all connections are re-directed to a designated backup. Checkpoint offers a High Availability Module for VPN-1 and FireWall-1

What is a Firewall/VPN Appliance?
A Firewall/VPN appliance is a dedicated hardware and software platform that is designed to do one task -- provide network security. Unlike firewall and VPN software that can be loaded on to existing servers, an appliance is a stand-alone solution. Appliances are pre-configured and tested for ease of deployment. Mission Critical Systems carries security appliances designed to meet a variety of business needs.