What is CIDR (Classless Addressing)? How to assign IP addresses efficiently
CIDR, or Classless Inter-Domain Routing, is a method used in IP addressing to allocate and assign IP addresses efficiently. It is based on the idea of subnetting, which allows a network to be divided into smaller subnets, each with its own unique range of IP addresses. CIDR replaces the traditional class-based system of IP addressing, known as classful addressing.
In classful addressing, IP addresses are divided into five classes: A, B, C, D, and E. Each class has a fixed range of addresses, with class A having the largest and class E reserved for experimental purposes. The problem with this system is that it often leads to inefficient allocation of IP addresses, as each class has a predetermined number of bits assigned to the network ID and the host ID.
CIDR solves this problem by allowing for a more flexible allocation of IP addresses. Instead of using fixed classes, CIDR allows the subnet mask to have any number of bits, providing more granularity in IP address allocation. This results in more efficient use of IP addresses, as the subnet mask can be adjusted to allocate only the necessary number of addresses to each subnet.
To assign IP addresses efficiently using CIDR, the following steps can be followed:
1. Determine the required number of subnets: Analyze the network requirements and determine how many subnets are needed.
2. Calculate the number of host addresses per subnet: Determine the number of hosts required in each subnet.
3. Determine the subnet mask: Calculate the subnet mask based on the required number of subnets and host addresses per subnet.
4. Allocate IP addresses: Assign IP addresses to each subnet, ensuring that each subnet falls within the calculated subnet mask.
5. Set up routing: Configure routing tables and protocols to ensure proper communication between subnets.
By following these steps and utilizing CIDR, IP addresses can be assigned efficiently, minimizing the wastage of addresses and optimizing network resources.
In conclusion, CIDR, or Classless Inter-Domain Routing, is a method that allows for more efficient allocation and assignment of IP addresses. By replacing the rigid class-based system of IP addressing, CIDR provides greater flexibility in allocating addresses to subnets. By following a structured approach and determining the required number of subnets and host addresses, administrators can effectively assign IP addresses using CIDR, resulting in optimized network addressing and resource allocation.
Reference Articles
Read also
[Google Chrome] The definitive solution for right-click translations that no longer come up.