In the world of computer networks, routing protocols play a vital role in defining how data is transferred from one network to another. It helps in determining the most optimal path for data transmission and ensures that the data reaches the intended destination without any errors. Routing protocols are broadly classified into two types, Classful and Classless routing. In this article, we’ll explore the key differences between these two types of routing protocols and how they work.
Classful Routing:
Classful routing protocols were developed in the early days of networking, and they divide IP addresses into three classes: A, B, and C. The classification is based on the number of bits used for the network and host portions of the IP address. Classful routing protocols do not send the subnet mask with the routing updates, making it essential for all devices in the network to have the same subnet mask.
Classful routing handles all IP traffic equally, regardless of the fact that some IP addresses may not be utilized in a particular network. For example, a Class A network uses a 24-bit subnet mask, allowing it to have up to 126 networks. In contrast, a Class C network employs an 8-bit subnet mask, allowing for up to 254 hosts. Classful routing protocols have limitations in their scalability, and they aren’t used extensively nowadays.
Classless Routing:
Classless routing protocols do not depend on the class of the IP address, and they transmit the subnet mask along with routing updates. Subnetting allows the network administrator to break a single network into smaller ones, thus optimizing the use of IP addresses.
Classless routing protocols, such as Open Shortest Path First (OSPF) and Routing Information Protocol version 2 (RIPv2), use variable-length subnet masks (VLSMs), allowing the subnet mask to be different for each network. This makes it easier to allocate IP addresses among different networks, and enables better scalability of the network.
Another routing protocol that uses classless routing is Border Gateway Protocol (BGP), which is commonly used in the internet service provider (ISP) networks. BGP uses path-vector routing, which helps in determining the most optimal path for data transmission across an extensive network.
Conclusion:
Routing protocols are a fundamental part of a computer network, and their proper configuration is critical for efficient data transmission. Classful and Classless routing are the two primary types of routing protocols that are used for data transmission. Classful routing protocols were developed earlier and were based on IP address classes A, B, and C. In contrast, Classless routing protocols do not depend on the IP address class, and they send the subnet mask with the routing updates. Classless routing protocols, such as OSPF and BGP, are widely used nowadays, owing to their scalability and better allocation of IP addresses.