A firewall is an integrated collection of security measures designed to prevent unauthorized electronic access to a networked computer system. It is also a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all computer traffic between different security domains based upon a set of rules and other criteria.
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria
Firewall solutions are available as either software or hardware (with software components). Software
firewalls protect each individual PC they're installed on. But to protect all your company's computers,
each must have a software firewall installed. That can get expensive and be difficult to maintain.
On the other hand, hardware-based firewall solutions protect all computers on your network.
A hardware-based firewall is easier to administer, too.The ideal firewall solutions integrate a hardware
firewall with software controls into a comprehensive security solution that includes virtual private
network (VPN) support, antivirus, antispam, antispyware, and content filtering capabilities.
Every SonicWALL Network Security Appliance solution delivers next generation Unified Threat Management
protection, utilizing a breakthrough multi-core hardware design and Reassembly-Free Deep Packet
Inspection for internal and external network protection without compromising network performance. Each
NSA Series product combines high-speed intrusion prevention, file and content inspection, and powerful Application Firewall controls with an extensive array of
advanced networking and flexible configuration features. The NSA Series offers an accessible, affordable
platform that is easy to deploy and manage in a wide variety of corporate, branch office and
distributed network environments.