IGP or Intradomain Routing Protocols are #Routing Protocol used to exchange routing information and forward packets within the Autonomous System (AS)# (intradomain).
It can be categorised into two main classes based on their prefer mechanism of information exchange:
AS is a #logical network segment that contains several Network Devices# especially Routers# under a common administration sharing a common routing strategy. An AS is typically identified using 16-bit autonomous system number (ASN) given by the American Registry of Internet Numbers (ARIN), an Internet Service Provider (ISP) or a network administrator. It is a basic unit in Routing inside AS involves #IGP whereas routing outside AS involves #EGP.