Routing Protocols
There are two types of dynamic routing protocols: Interior Gateway Protocols (IGP) and External
Gateway Protocols (EGP). IGPs are used to exchange routing information within an autonomous system
(AS), which is a collection of routing domains under the same administrative control the same routing
domain. An EGP, on the other hand, is used to exchange routing information between different ASs.
IGPs can be broken into two classes: distance-vector and link-state, and can also be broken into two
categories: classful routing protocols and classless routing protocols.