Proxy Firewall

 

A firewall is a network security device that separates a trusted internal network from an external network that is considered untrusted, such as the Internet. It regulates incoming and outgoing network traffic based on pre-configured security rules. Firewalls play a central role in protecting networks from unauthorized access, malicious activity, and potential threats, and can exist as hardware, software, Software as a Service (SaaS), or a public or private (virtual) cloud.

Firewalls inspect network packets to implement security policies, effectively preventing unauthorized users and potentially harmful data from entering or leaving the network. A firewall primarily acts as a gatekeeper, checking every network packet and deciding whether to allow or block the packet based on pre-configured rules. This ensures that only traffic that is deemed safe and legitimate passes through the firewall.

In addition to these core functions, today's next-generation firewalls (NGFWs) have many other features to improve network security. These include deep packet inspection, application visibility and control, intrusion detection and prevention, malware protection, URL filtering, and more.

Types of Firewalls

Packet Filter Firewalls

These firewalls inspect all data packets that pass through them and filter them based on parameters such as source and destination IP addresses, port numbers, and protocol types. These firewalls are relatively simple and inexpensive, but because they cannot inspect the contents of packets, they are less effective against complex attacks.

Proxy Firewall

A proxy firewall is an early type of firewall device that acts as a gateway from one network to another for specific applications. By preventing direct connections from outside the network, a proxy server can provide additional functionality such as content caching and security. However, this can also impact throughput capabilities and the applications they can support.

Stateful Inspection Firewall A

stateful inspection firewall is now considered a traditional firewall, and allows or blocks traffic based on status, port, and protocol. It monitors all activity from the beginning to the end of a connection. Filtering decisions are based on both administrator-defined rules and context, using information from previous connections and packets belonging to the same connection.