Final answer:
Routing protocols are categorized into Interior Gateway Protocols (IGPs) for routing within an autonomous system and Exterior Gateway Protocols (EGPs) for routing between different autonomous systems.
Step-by-step explanation:
The two main categories that routing protocols fall under are Interior Gateway Protocols (IGPs) and Exterior Gateway Protocols (EGPs). IGPs are used for routing within a single autonomous system, whereas EGPs are used for routing between different autonomous systems. Examples of IGPs include Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Intermediate System to Intermediate System (IS-IS), while the Border Gateway Protocol (BGP) is an example of an EGP.