The internet is organized into what?

Question

In order to provide flexibility to the various ISPs to run and manage their own parts of the internet, including the ability to run routing protocols of their own choosing, the internet is organized into     

a- automatic systems        

b- autonomous systems    

c- so called "fiefdoms"

d- administrative systems 

e- None of the above

Answer 1

An autonomous system or AS

An AS is a collection of connected networks represented by their routing prefixes under the control of one or more network operators. Each AS connects to 1 or more other AS's.

Imagine an AS as a post office. Each Post office delivers mail to specific addresses in its Zip Code. For a piece mail to be delivered in another Zip Code it must travel from one post office to another post office along the path until it reaches the one that serves the addresses in the appropriate Zip Code.

Similarly, AS's on the internet use routing protocols (BGP) to pick the most efficient path to deliver IP traffic from one network to another.