Information Technology IT – 14 Communications technology | e-Consult

A firewall acts as a barrier between a trusted network (e.g., your home or company network) and an untrusted network (e.g., the internet). Its primary function is to control network traffic by examining incoming and outgoing packets and blocking those that don't meet pre-defined security rules. It essentially acts as a gatekeeper, allowing legitimate traffic through while preventing malicious or unauthorized traffic.

There are several types of firewall architectures:

• Packet Filtering Firewalls: These examine the header information of each packet (source/destination IP addresses, ports, protocols) and make decisions based on a set of rules.

  • Advantages: Fast and relatively simple to implement.
  • Disadvantages: Limited security; can be easily bypassed with crafted packets.

• Stateful Inspection Firewalls: These keep track of the state of network connections (e.g., whether a connection is established, in progress, or closed). They examine packets in context, allowing only packets that are part of an established connection.

  • Advantages: More secure than packet filtering; better at preventing attacks that exploit connection states.
  • Disadvantages: More resource-intensive than packet filtering.

• Proxy Firewalls: These act as intermediaries between internal and external networks. All traffic passes through the proxy, which inspects the traffic and can block malicious requests.

  • Advantages: High level of security; can hide internal network addresses.
  • Disadvantages: Can be slower than other types of firewalls; more complex to configure.