Introduction to Internet Routing & Functions Before moving into Internet Routing and Functions let me start off with a small overview of routing protocols. A routing protocol specifies how routers communicate with each other to distribute information. We don’t need to configure every route on each router in the network manually. (like in static route). IGP and EGP IGP stands for Interior Gateway Protocol which is used by gateways to exchange routing information within an AS (Autonomous System). An AS is also known as a routing domain. This could be like a Corporate network, Campus Network, ISP (Internet Service Provider) network. EGP stands for Exterior Gateway Protocol, used by gateways to exchange routing information between ASs. In EGP, routing path selection is based on network policies and network administrator configured rule-sets. Currently the Internet uses BGP4 (Border Gateway Protocol version 4). IGP There are two main categories of IGP. LS (Li...