A classful routing protocol can communicate which types of information in its updates? (Choose three)

A classful routing protocol communicates several types of information in its updates, which include metrics, network numbers, and autonomous system (AS) numbers.

Metrics are crucial as they provide a way for routers to measure the cost associated with sending packets over a network. This cost can be based on various factors such as hop count, bandwidth, or delay, depending on the specific classful routing protocol used.

Network numbers are important as they denote the actual networks that the protocol can reach. In classful routing protocols, which do not utilize subnetting, the network address represents the entire network segment, and all devices within that network share the same network number.

Autonomous system (AS) numbers are utilized to identify a collection of IP networks and routers under the control of a single organization that presents a common routing policy to the internet. This provides additional context for how routing information is propagated and managed across independent networks.

In contrast, classful routing protocols do not communicate subnetwork masks in their updates because these protocols assume a default class-based mask for the networks they operate within. As a result, classful protocols are not able to handle variable-length subnet masking (VLSM) and can lead to inefficiencies in routing.