Before networks became large, there were no internal and external gateway protocols. A network simply ran on a generic routing protocol. This eventually ran into problems, so the Routing Information Protocol (RIP) was developed and used as the sole routing protocol for many years [1]. As the Internet grew, however, this single routing protocol could no longer handle all traffic. For this reason, numerous other routing protocols have been developed over time to meet routing needs. One of several gateway protocols developed was the Border Gateway Protocol (BGP), classified as the External Gateway Protocol (EGP). BGP was developed in January 1989 at the 12th Internet Engineering Task Force Meeting in Austin, Texas, by two men, Yakov Rekhter and Kirk Lougheed [1]. Interestingly, the initial design of BGP was detailed on a napkin, which shortly thereafter was transferred to paper and quickly implemented. From this initial napkin design came the foundation of the gateway protocol, BGP, which will be discussed in the remainder of this article. OVERVIEW: BASICS: BGP is the largest routing protocol in existence as it must find all possible routes and carry information around the world. However, because it is so large, it is also the slowest routing protocol. Mainly, BGP is used to connect local networks with external networks to gain access to the Internet or other organizations [2]. Furthermore, BGP communication systems must exchange reachability information over a network with other BGP systems [3]. This information includes a list of autonomous systems (AS), where you can build a table showing possible routing cycles. Autonomous systems will be discussed in detail later. To swap the n...... middle of the card ......ed list of parameters, which is part of the reason BGP is so complex. From these parameters, BGP must select a single path that it believes is best for going from a host to a network. This selection algorithm analyzes the metrics of each path to determine which path to install in the forwarding routing table [2]. Standard BGP policy configurations can also affect the BGP forwarding path [2]. The information that is attempted to be accessed over the Internet is then sent using the forwarding table created by BGP. This also requires the best route to be sent to external BGP neighbors. Typically, BGP speakers only advertise routes to peers that it uses itself [3]. BGP assigns the first valid route as the current best route, then compares it to the next route in the list until it finds the best route in the route list valid. The following figure shows