Firewalls

Business needs today are driving enterprise networks to be more open than ever before. Whether due to partnerships, outsourcing, tele-working, or remote access, the enterprise network perimeter is vanishing, making the network perimeter-based security model less and less effective. As a result, many enterprises have taken a layered approach to securing open networks by implementing a centrally managed personal firewall & security policy enforcement solution.

A firewall is a system designed to prevent unauthorised access to or from a private network. Firewalls can be implemented as both firewall hardware and firewall software, or a combination of both. Firewalls are frequently used to prevent unauthorised 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. A firewall is considered a first line of defense in protecting private information. For greater security, data can be encrypted.

A firewall software has the basic task of controlling traffic between different zones. Typical zones include the Internet (a zone with no trust) and an internal network (a zone with high trust). The ultimate goal is to provide controlled connectivity between zones of differing trust levels through the enforcement of a firewall security policy and connectivity model based on the least privilege principle.