What distinguishes classful routing protocols from classless routing protocols?

Classful routing protocols are defined by their handling of IP address classes, specifically that they do not include subnet mask information in their routing updates. This means that when a classful protocol sends out routing updates, it assumes that all routers on the network understand the default subnet mask determined by the address class (Class A, B, or C). For example, a Class A address would use a default mask of 255.0.0.0, while a Class C address uses 255.255.255.0. This can lead to limitations in flexibility, especially in networks that use variable-length subnet masking (VLSM) or need to operate across different subnet configurations.

In contrast, classless routing protocols (like OSPF or EIGRP) include subnet mask information with their routing updates, allowing for more sophisticated and flexible network architectures that utilize variable-length subnets. This adaptability is crucial in modern network designs where efficient IP address utilization is necessary.

The other options do not accurately reflect the fundamental distinctions between classful and classless protocols. For example, speed is not inherently a distinction between these protocol types; both can have variable performance based on different factors such as network size and design. Classful protocols are not limited to just large