Understanding IP Subnetting
IP subnetting is the process of dividing a large IP network into smaller, more manageable sub-networks, or "subnets." This is essential for network organization, security, and efficiency. By using a subnet mask, network administrators can determine which part of an IP address represents the network and which part represents the host.
Key Concepts
- IP Address: A unique 32-bit number that identifies a device on a network. It's typically written in dot-decimal notation (e.g., 192.168.1.1).
- Subnet Mask: A 32-bit number that masks an IP address and divides the IP address into network address and host address. The 1s in the mask represent the network portion, and the 0s represent the host portion.
- Network Address: The first address in a subnet. It represents the subnet itself and cannot be assigned to a host.
- Broadcast Address: The last address in a subnet. It's used to send a message to all hosts on the subnet simultaneously.
- Usable Hosts: The range of IP addresses within a subnet that can be assigned to individual devices. This range excludes the network and broadcast addresses.
- CIDR (Classless Inter-Domain Routing): A method for allocating IP addresses and routing IP packets. The CIDR notation (e.g., /24) represents the number of leading 1s in the subnet mask, providing a shorthand for the mask itself.