The BGP Routing Protocol Explained

Which of the following BEST describes the BGP routing protocol?

A.

distance vector

B.

hybrid

C.

static

D.

link state.

B.

The Border Gateway Protocol (BGP) is a routing protocol used to exchange routing information among different Autonomous Systems (AS) on the Internet. It is a path-vector protocol, which means it considers not only the shortest path to a destination network but also the policies that determine which path to use.

BGP is considered a hybrid routing protocol because it combines aspects of both distance vector and link-state protocols. Like distance vector protocols, BGP routers exchange routing information with their neighbors, but unlike them, BGP routers advertise the full path of the route to the destination network, rather than just the next hop. This allows BGP to consider policies such as the AS path length, the quality of service, and the cost of the path when determining the best path to use.

Additionally, BGP uses a link-state database to keep track of the network topology within an AS, which allows it to perform loop prevention and load balancing effectively. BGP routers exchange link-state information only within their AS and not with other ASes. Therefore, BGP is not a pure link-state protocol.

In conclusion, BGP is a hybrid routing protocol that combines aspects of both distance vector and link-state protocols. It uses path-vector methodology to exchange routing information between ASes, and link-state information to maintain the network topology within an AS.