What is CIDR Notation?

CIDR (Classless Inter-Domain Routing) notation is a compact method for specifying IP address ranges using a base IP address followed by a slash and prefix length. For example, 192.168.1.0/24 represents all 256 addresses from 192.168.1.0 to 192.168.1.255.

Prefix Length, Host Bits, and Address Ranges

A CIDR notation consists of an IP address and a suffix indicating the number of fixed bits in the network prefix. The remaining bits define the host range. A /24 network has 24 fixed bits and 8 variable bits, allowing 256 addresses. A /16 has 65,536 addresses. A /32 represents a single IP. When a website blocks a CIDR range, all IPs within that range are affected. CIDR is used in routing tables, firewall rules, access control lists, and proxy subnet documentation.

Understanding CIDR is practical for proxy work. If a target blocks 45.32.100.0/24, all 256 IPs in that range are gone. When evaluating a proxy pool from Hex Proxies accessible through gate.hexproxies.com:8080, seeing IPs spread across hundreds of different /24 ranges means a single range-level block only removes a tiny fraction of available IPs.

CIDR Awareness for Pool Evaluation

Understanding CIDR notation is essential for proxy users who manage IP allowlists, configure firewall rules, or evaluate proxy pool diversity. When a target blocks a /24 range, all 256 IPs in that subnet become unusable. Hex Proxies distributes IPs across diverse CIDR ranges to minimize the impact of range-level blocks on overall pool availability.