I have been busy writing some posts on some general topics for those readers who want some high-level overviews of various network terms and items.
Border Gateway Protocol (BGP) is the core routing protocol used to exchange information about network reachability between routers in the Internet. BGP enables routers to make informed decisions about the routes to reach specific destinations, ensuring that internet traffic is delivered efficiently and reliably.
Here are some key points about BGP:
- BGP is a Path Vector Protocol BGP is a path vector protocol, meaning that it uses information about the paths to reach specific destinations, as well as information about the attributes of those paths, to make routing decisions. This allows BGP to choose the best paths for internet traffic, taking into account factors such as network performance, network availability, and network security.
- BGP is hierarchical, meaning that it uses multiple levels of routers to exchange information and make routing decisions. The highest level of routers, known as Autonomous Systems (AS), make decisions about how to route internet traffic within their own networks. Lower-level routers, known as BGP routers, make decisions about how to route internet traffic between different ASs.
- BGP is a Policy-Based Routing Protocol. BGP allows administrators to specify routing policies, which determine how traffic should be routed based on specific criteria. This allows organizations to control the routes that their internet traffic takes, for example, to ensure that traffic is routed over high-performance connections, to avoid congested networks, or to comply with regulatory requirements.
- BGP is a slow converging protocol, meaning it takes time for routers to update their routing tables in response to changes in network conditions. This can result in temporary black holes, where internet traffic is dropped, or suboptimal routing, where traffic is sent over slow or congested paths. To mitigate these risks, BGP uses multiple mechanisms to detect changes in network conditions and update routing tables, such as route reflectors, confederations, and communities.
- BGP is critical to the Internet’s operation, enabling routers to decide how to route internet traffic between different networks. BGP is used by nearly every organization that connects to the Internet, and it forms the backbone of the Internet’s infrastructure.
In conclusion, Border Gateway Protocol (BGP) is an essential component of the Internet’s infrastructure, enabling routers to make informed decisions about the routes to reach specific destinations. By understanding the key features of BGP, organizations can ensure that their internet traffic is delivered efficiently and reliably and can take advantage of the policy-based routing capabilities of BGP to control the routes that their traffic takes.
Some Further Reading on BGPj2networks family of sites