Which Dynamic Routing Protocol was Developed to Interconnect Different Internet Service Providers?

Well this is a question from the CCNA Exam, and I would like to explain this in my way, hopefully, you will enjoy and learn from the post.

To explain this better, I would like to divide the question into the following two parts and explain each one of them first,

• Dynamic routing protocol
• Internet Service providers 

What is Dynamic routing protocol

while we will be discussing Dynamic routing protocol in detail in an upcoming post, but to give an overview and provide a good answer to this question the dynamic routing protocol could be explained as follows:

in dynamic routing, the routers do not need the administrators to configure events of any changes like they do in the static routing, but instead, they learn the routing information automatically and add the route to its routing table. When a router uses a dynamic routing protocol, it saves the best route to its routing database and can also find an alternative path if the original one fails.

Some of the examples of dynamic routing protocols are:

• Open Shortest Path First (OSPF)
• Enhanced Interior Gateway Routing Protocol (EIGRP)
• Routing Information Protocol (RIP)
• Border Gateway Protocol (BGP)

What are Internet Service Providers?

A corporation, or company that provides Internet connections and services to people and companies is known as an Internet service provider (ISP). Some ISPs may also provide services of software packages like Internet browsers, websites, email services. Furthermore, all of these ISP’s are also interconnected with each other to share information, exchange data, and interconnect their customers.

When different ISP’s interconnect with each other, they create a big network, a huge one. In the huge network topologies, where a lot of different network devices are connected with each other, it is not possible for an administrator to keep and maintain a manual routing table, that is why dynamic routing protocols are used. Furthermore, each ISPs have their own routing policy, so they are defined with different autonomous system numbers.

Among all the different dynamic routing protocols, the border gateway protocol (BGP) is used to exchange routing information between different autonomous system numbers.

So our answer to this question is “BGP is a protocol developed to interconnect different levels of ISPs as well as ISPs and some of their larger private clients.”