What is the main difference between RIPv1 and RIPv2?

The main difference between RIPv1 and RIPv2 is that RIPv2 supports subnet masks and Classless Inter-Domain Routing (CIDR), which allows for more efficient and flexible IP address allocation compared to RIPv1.

RIPv1 is a classful routing protocol, meaning it does not send subnet mask information with its routing updates. As a result, it operates based on the default subnet masks associated with the class of the IP address (Class A, B, or C). This limitation can lead to inefficient address space usage and problems when networks require variable-length subnet masking (VLSM).

On the other hand, RIPv2 is a classless routing protocol that includes subnet mask information in its routing updates. This enhancement allows for better support of CIDR, enabling networks to utilize IP address space more effectively. With RIPv2, routers can learn about routes that use different subnet masks and can thus accommodate a wider range of network configurations and sizes.

This capability is particularly important as it allows for more sophisticated network designs and optimizations in routing, accommodating varying sizes of subnets within the same network architecture.