Computer Networking Basics
Which correctly describes dynamic routing?
- AAn administrator configures routes on each router by hand, and the same routes stay in use after a failure until the configuration is changed
- BRouters exchange route information using routing protocols and automatically switch to another path when a failure makes a route unusable
- CA route is chosen at random for each packet to spread the load evenly over several paths
Show answer and explanation
Answer: B. Routers exchange route information using routing protocols and automatically switch to another path when a failure makes a route unusable
Static routing means an administrator configures routes by hand. It is simple and predictable, and suits small networks or the default route of a site with only one exit, but it does not switch over automatically after a failure. In dynamic routing, routers exchange information with routing protocols such as OSPF or BGP to build their routing tables automatically, and recalculate another path when a link fails. On the internet, routes between organizations' networks (autonomous systems) are exchanged with BGP. Real networks commonly combine both.
- A. That describes static routing.
- B. Correct. It rebuilds routing tables automatically in response to failures.
- C. Even in dynamic routing, paths follow the routing table computed by the protocol; they are not random.