Web and DNS Filtering

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Web Filtering

• Web filtering or content filtering is used to control or restrict the content users can access on the internet
• Crucial for businesses, educational institutions, and parents to ensure safe and productive internet use

Different types of web filtering techniques

• Agent-Based Web Filtering
  • Involves installing an agent on each device
  • Monitors and enforces web usage policies
  • Effective for remote and mobile workers
• Centralized Proxy
  • Uses a proxy server as an intermediary between an organization’s end users and the Internet
  • Evaluates and controls web requests based on policies
  • If the request does not conform with the policies, the request is simply blocked or denied
• URL Scanning
  • Analyzes website URLs to check for matches in a database of known malicious websites
• Content Categorization
  • Classifies websites into categories (e.g., social media, adult content) and blocks or allows categories based on policies
• Block Rules
  • Specific guidelines set by organizations to prevent access to certain websites or categories, often used to address security threats
• Reputation-Based Filtering
  • Blocks or allows websites based on a reputation score determined by third-party services, considering factors like hosting malware or phishing

DNS Filtering

• DNS filtering (Domain Name System filtering) blocks access to specific websites by preventing the translation of domain names to their IP addresses
• Users' devices request domain name translation from DNS servers; if the domain is on the block list, the server withholds the IP address to prevent access
• Commonly used to enforce internet usage policies, block inappropriate content, and protect against malicious websites
• Often employed by schools, universities, and organizations to ensure safe and educational internet usage