Cisco CCNA mock exam questions sample test – Question 401

.Which of the following statements are true when discussing link state and distance vector routing protocols? (Choose all that apply.)

A. After convergence, routing advertisements are only triggered by changes in the network with distance vector protocols
B. Packets are routed based upon the shortest path calculated by an algorithm with link state protocols
C. Only one router in an OSPF area can represent the entire topology of the network
D. Distance vector protocols send the entire routing table to a neighbor
E. Distance vector protocols send updates regarding the status of their own links to all routers in the network
F. Link-state protocols place a high demand on router resources running the link-state algorithm
G. Distance vector protocols require a hierarchical IP addressing scheme for optimal functionality
H. Link-state protocols use hello packets and LSAs from other routers to build and maintain the topological database
I. Link-state protocols require a hierarchical IP addressing scheme for optimal functionality.

Correct Answer: BDFHI

Explanation:
The following statements are true of link-state and distance vector routing protocols:
Packets are routed based upon the shortest path calculated by an algorithm with link state protocols.
Distance vector protocols send the entire routing table to a neighbor.
Link-state protocols place a high demand on router resources running the link-state algorithm.
Link-state protocols use hello packets and LSAs from other routers to build and maintain the topological database.
Link-state protocols require a hierarchical IP addressing scheme for optimal functionality.
Link state protocols like OSPF use the Shortest Path First algorithm to calculate the shortest path based on a metric called cost, while distance vector protocols like RIP consider only
hop count when determining the best route. Running the algorithm places a high demand on router resources. Distance vector protocols are required to send the entire routing table
with each update, while link state protocols only send updates when required by changes in the network. Therefore, less traffic is created with link state protocols.
Sending routing advertisements after convergence only when changes occur in the network is a characteristic of link state protocol’s not distance vector protocols. With distance
vector protocols, updates occur regularly and include the entire routing table.
All routers in an OSPF area can represent the entire topology of the network, not just one.
Distance vector protocols do not send updates regarding the status of their own links to all routers in the network. Updating link status is a characteristic of link state protocols.
Distance vector protocols send the entire routing table.
Distance vector protocols do NOT require a hierarchical IP addressing scheme for optimal functionality. Link-state protocols do require this for optimal functionality, as it supports more
efficient route aggregation or summarization. This reduces the number of routes in the table and the number of calculations required by the SPF algorithm, thereby lowering router
resource demand.
Objective:
Routing Fundamentals
Sub-Objective:
Compare and contrast distance vector and link-state routing protocols
References:
Cisco>Internetworking Technology Handbook>Routing Basics>Link-State versus Distance Vector