Final answer:
When choosing an interior gateway routing protocol, speed of convergence and scalability are two critical factors, as they indicate how quickly the protocol adapts to changes and how well it can handle network growth.
Step-by-step explanation:
The choice of an interior gateway routing protocol is influenced by various factors that affect the performance and the efficient operation of a network. When deciding which interior gateway routing protocol to use, two important factors to consider are the speed of convergence and scalability.
Speed of convergence refers to how quickly the routing protocol can react to changes in the network, such as a router failure or a new network being added, and update all routers with the new routing information. A faster convergence time is generally more desirable because it means that the network will be able to return to normal operation quicker after a change or failure.
Scalability is also critical since it indicates how well the routing protocol can accommodate growth. As networks grow in size, with more routers and links being added, the chosen protocol must be able to manage the increasing complexity without degrading network performance significantly.