About IP Subnetting & CIDR
Subnetting is the practice of dividing a network into two or more smaller networks (subnets). Classless Inter-Domain Routing (CIDR) is an IP addressing scheme that improves the allocation of IP addresses. Instead of using traditional Classes A, B, and C, CIDR uses a slash prefix (such as /24) to denote the number of shared network routing bits, allowing much more flexible subnet definitions.
Key Subnet Terms
- Network Address: The first address in the subnet, used to identify the subnet itself. Cannot be assigned to hosts.
- Broadcast Address: The last address in the subnet, used to send data packets to all hosts in the subnet. Cannot be assigned to hosts.
- Usable Host Range: The range of IP addresses between the Network and Broadcast addresses that can be assigned to devices.