Firewall Protection

Protection Tools: Firewalls

A firewall is a monotonous, relentless filter for data packets that a computer exchanges with the Internet. Think of a post-office worker assigned to permit mail for certain city addresses and deny everything else — everything that is not specifically allowed.

The worker checks if the recipient lives on an allowed street and if the sender is banned. If it's a “green light,” the package goes through. In Internet terms, an IP address is analogous to a street address, and a port is analogous to a building with a designated function (police department, hospital, post office, etc.).

Beyond basic addressing, firewalls can also filter based on:

• Type of package (protocol)
• Time and date restrictions
• Event-triggered timing
• Content of the package
• Confirmation or clearance of the sender's identity

Passive (Standard) Firewalls

Almost everyone with a broadband connection uses a basic passive firewall. The most common example exists in every home router with two simple rules: allow all traffic sent from home into the Internet, and block everything trying to enter except for replies to outgoing requests. Windows, Mac, and Linux computers all come with built-in firewalls activated by default. These are driven by a pre-written set of rules with modest capabilities to adapt.

Active Firewalls

Active firewalls provide much stronger security. They resemble an analytical division rather than a simple postman — they can introduce new rules on the fly and override existing ones when attacks are detected. Active firewalls are dynamic because they:

• Recognize hostile patterns of Internet traffic
• Obey real-time block lists for known threats
• Analyze suspicious events in real-time

Drawbacks

• High-quality, intelligent firewalls are not free — they typically require subscriptions and frequent updates
• Heavy censorship provides more safety but also impacts system performance and Internet speed
• Legitimate applications using non-standard traffic may be blocked by default rules, requiring manual configuration

Business Firewalls

Business firewalls are often used to limit potential distractions to employees. It's common practice to block access to entertainment, chat websites, and social networks such as YouTube, Facebook, and messaging platforms. On a larger scale, firewalls are also used for content control and protecting children from unwanted Internet content.