Border Gateway Protocol

Border Gateway Protocol or BGP is a standard gateway protocol that is responsible for exchanging routing information across autonomous systems. In simple words Border Gateway Protocol makes internetwork. Its protocol underlies the global routing system of the internet. It manages packets to route from one network to the other. This all is functioned through the exchange of routing and reachability information. It directs packets between autonomous systems. It has expanded on its original purpose of carrying internet reachability information and now is able to carry multicast, VPN Network, and many other varieties of data.

BGP has the capability to connect any internetwork of the autonomous system using an arbitrary topology. BGP is also classified as a path vector protocol but also a distance vector routing protocol sometimes. The functioning of the internet depends on BGP because without this no one can even do a simple Google search or send a simple email. You can compare BGP with the GPS navigation system.

The time when the internet was not more than a tiny cloud server, routing between nodes was used to be static. Then came the use of defining network nodes and to connect as per the need. Now the incorporated network of internet needs a more dynamic routing system. The type of network architecture it follows has an autonomous system that controls a collection of connected routing prefixes.

Working with BGP is unique in itself. Every router inside BGP’s routing table and they control the packed and how they have to be directed. There is a Routing Information Base (RIB) where there is a data table is stored on the BGP router. The information contained inside the RIB from directly connected external peers along with the internal peers. They analyze the routes and how the information should be published. It simultaneously updates the routing table as soon as the changes occur.

There is so much to offer by BGP and the topmost priority is given to network stability. The routers quickly adapt to send packets through alternate channels. So if one of them goes down the other one instantly gets ready. BGP makes sure that routing decisions are taken based on paths, rules, and network policies. These network policies are those that are set by the network administrator. The topology to communicate routing information with the client-server by initiating a BGP session by sending a request to the web server.

The BGP updates router table information as and when something changes. The connections between peers must be set up manually with peer addresses programmed in both ends. BGP helps in making the best path decisions that are based on current reachability. It also takes into account hop counts and other path characteristics. When multiple paths are available the major hosting facility BGP policies communicate as per the organization’s preference. They can also control route advertisement behavior among peers. The networking of BGP is based on TCP/IP. It considers all the peering partners that the router currently holds and stores the information in the RIB. But BGP should also be protected from threats like BGP hijacking. Thus it helps in building up peering relationships and implementing protocols.