IP Blocking

IP blocking is a security technique used to restrict access to a network, server, or service by denying requests from specific IP addresses or ranges. It is commonly implemented in firewalls, web servers, or network devices to prevent malicious traffic, such as from attackers, bots, or spam sources. This method helps protect systems from unauthorized access, DDoS attacks, or abuse by filtering traffic based on IP addresses.

Also known as: IP Banning, IP Filtering, IP Blacklisting, IP Address Blocking, IP Denylist

Why learn IP Blocking?

Developers should learn IP blocking to enhance security in applications and infrastructure, especially when dealing with public-facing services like websites or APIs. It is crucial for mitigating threats like brute-force attacks, scraping, or geo-restrictions, and is often used in conjunction with other security measures like rate limiting or WAFs. Understanding IP blocking helps in configuring firewalls, managing access control lists, and implementing security policies in cloud platforms or on-premise systems.

Learning Resources

• docs: OWASP IP Blocking Guide
• tutorial: Cloudflare IP Blocking Tutorial
• docs: AWS WAF IP Set Rules Documentation
• docs: Nginx IP Blocking Configuration