Section 21.203 Web and DNS Filtering

Question 1

Web Filtering

Answer 1

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

Question 2

Different types of web filtering techniques

Agent-Based Web Filtering

Answer 2

Involves installing a samll piece of software known as an agent on each device

Monitors and enforces web usage policies

Effective for remote and mobile workers

Question 3

Different types of web filtering techniques

Centralised Proxy

Answer 3

Uses a proxy server as an intermediary between an organizations 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

Question 4

Different types of web filtering techniques

URL Scanning

Answer 4

Analyses website URLs to check for matches in a database of known
malicious websites

Question 5

Different types of web filtering techniques

Content Categorisation

Answer 5

Classifies websites into categories (e.g., social media, adult content) and
blocks or allows categories based on policies

Question 6

Different types of web filtering techniques

Block Rules

Answer 6

Specific guidelines set by organisations to prevent access to certain websites or categories, often used to address security threats

Question 7

Different types of web filtering techniques

Reputation-Based Filtering

Answer 7

Blocks or allows websites based on a reputation score determined by
third-party services, considering factors like hosting malware or phishing

Question 8

DNS Filtering

Answer 8

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