BGP Border Gateway Protocol
All of the dynamic routing protocols we have seen so far were IGP, the Interior Gateway Protocol. BGP protocol is an EGP, exterior gateway protocol. If you ask what is the difference between IGP and EGP, as their names suggest, internal gateway protocols can forward within the same autonomous system, while external gateway protocols can perform packet routing between different autonomous systems. To explain through an example, when you make a request to addresses such as facebook or Google from Turkey, your packages pass through the routers of many different Internet Service Providers until they go to America. If you are using Türk Telekom in your location even in Turkey and you make a request to the web page of an institution served by Süperonline, your packages are exposed to the BGP routing protocol. Because when routing between routers in different autonomous systems like this, an external gateway protocol such as BGP is used. To sum up, the most important factor that distinguishe