Help Topic: Internet - Firewall

Firewall

In computing, a firewall is a piece of hardware and/or software which functions in a networked environment to prevent some communications forbidden by the security policy, analogous to the function of firewalls in building construction.

A firewall has the basic task of controlling traffic between different zones of trust. Typical zones of trust 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 security policy and connectivity model based on the least privilege principle.

DoS Attacks

A denial-of-service attack (short: DoS attack) is an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services by consuming the bandwidth of the victim network or overloading the computational resources of the victim system.

Port Scans

Port Scans are a favoured method to detect potential weak points in your LAN.

A Port Scanner tries to gather information about active services on a maschine by connecting to a server (Connect Scan) or getting answer to invalid data packets (Stealth Scan).

Service Filtering

Using Service Filtering will deny answers of certain (internal) services to attacks form the outside.