|Exam 200-120||Question id=41||IP Routing Technologies|
What are drawbacks of implementing a link-state routing protocol?
The sequencing and acknowledgment of link-state packets|
The requirement for a hierarchical IP addressing scheme for optimal functionality|
The high volume of link-state advertisements in a converged network|
The high demand on router resources to run the link-state routing algorithm|
The large size of the topology table listing all advertised routes in the converged network|
Link State routing protocols converge more quickly than distance vector routing protocols, through the use of flooding and triggered updates. In link state protocols, changes are flooded immediately and computed in parallel. Triggered updates improve convergence time by requiring routers to send an update message immediately upon learning of a route change. These updates are triggered by some event, such as a new link becoming available or an existing link failing. The main drawbacks to link state routing protocols are the amount of CPU overhead involved in calculating route changes and memory resources that are required to store neighbor tables, route tables and a complete topology database.