Netmasking

Netmasking is a fundamental networking concept used to divide an IP address into a network portion and a host portion. This division is crucial for routing traffic efficiently within a network and across the internet. A netmask is a 32-bit number, typically represented in dotted-decimal notation just like an IP address. It consists of a series of contiguous 1s followed by a series of contiguous 0s. The 1s indicate the network portion of the IP address, while the 0s represent the host portion. When a network device performs a bitwise AND operation between an IP address and its corresponding netmask, the result is the network address. This network address is used to identify the specific network to which a device belongs. The host portion of the IP address is then used to uniquely identify a device within that network. Different subnet masks allow for the creation of various subnet sizes, enabling administrators to segment larger networks into smaller, more manageable subnets. This process, known as subnetting, improves network performance, security, and administration. Common netmasks include 255.255.255.0 for a /24 network, which provides 254 usable host addresses, and 255.255.0.0 for a /16 network, offering a much larger number of host addresses.