Subnetting :

 Subnetting is the process of dividing a large network into smaller subnetworks, known as subnets. This allows for more efficient use of IP addresses and can help improve network performance and security.

There are several types of networks, including Local Area Networks (LANs), Wide Area Networks (WANs), and Metropolitan Area Networks (MANs).

A LAN is a network that covers a small geographic area, such as a home, office, or campus. LANs typically use Ethernet or Wi-Fi technologies to connect devices, and are often managed by a single organization.

A WAN is a network that covers a larger geographic area, such as a city, country, or even the world. WANs often use leased lines, satellites, or other high-speed connections to connect devices, and are typically managed by multiple organizations or service providers.

A MAN is a network that covers a larger geographic area than a LAN, but smaller than a WAN. A MAN typically covers a single city or metropolitan area, and may be managed by a single organization or a consortium of organizations.

When subnetting a network, you need to determine the number of subnets required, and the number of hosts that each subnet will need to support. You can calculate the subnet mask, network ID, and broadcast IP address based on these requirements.

The subnet mask is a 32-bit number that indicates which portion of an IP address represents the network ID, and which portion represents the host ID. It is often expressed in dotted decimal notation, such as 255.255.255.0. The number of bits set to 1 in the subnet mask indicates the number of network bits, while the remaining bits represent the host bits.

To calculate the subnet mask for a given number of subnets, you can use the formula 2^n - 2, where n is the number of bits required to represent the number of subnets. For example, if you need to create 4 subnets, you would require 2 bits (since 2^2 = 4), so the subnet mask would be 255.255.255.192 (or /26 in CIDR notation).

To calculate the number of hosts per subnet, you can use the formula 2^h - 2, where h is the number of bits available for the host ID. The -2 is because the first and last addresses in each subnet are reserved for the network ID and broadcast IP address, respectively.

To calculate the network ID for a given subnet, you can perform a bitwise AND operation between the IP address and the subnet mask. For example, if the IP address is 192.168.1.10 and the subnet mask is 255.255.255.0, the network ID would be 192.168.1.0.

To calculate the broadcast IP address for a given subnet, you can perform a bitwise OR operation between the network ID and the bitwise NOT of the subnet mask. For example, if the network ID is 192.168.1.0 and the subnet mask is 255.255.255.0, the broadcast IP address would be 192.168.1.255.

Overall, subnetting can be a complex topic, but it is an important concept to understand for network administrators and engineers.