IGP
The Internal Gateway Protocol (IGP for short) is used to promote the exchange of routing information between routers within an autonomous system. The IGP can be used on the one hand to disseminate information about the availability of routers and on the other hand to check the possible paths for data packets. This exchange of information is permanent within an autonomous system. The information obtained then uses the Internet Protocol (IP) or other network protocols to determine the best possible path for data packets.