CCNA2 Chapter 4

1. What does the RIP holddown timer do?
ans:
instructs routers to ignore updates, for a specified time or event, about possible inaccessible routes

2. What metric does the RIP routing protocol consider to be infinity?
ans:
16

3. What is a routing loop?
ans:
a condition where a packet is constantly transmitted within a series of routers without ever reaching its intended destination

4. Which two statements are true regarding the function of the RIPv1 routing updates? (Choose two).
ans:
updates are broadcast at regular intervals
broadcasts are sent to 255.255.255.255

5. Which of the following can exist in a distance vector network that has not converged? (Choose three.)
ans:
routing loops
inconsistent traffic forwarding
inconsistent routing table entries

6. Refer to the exhibit. What path will packets from the 192.168.1.0/24 network travel to reach the 10.0.0.0/8 network if RIP is the active routing protocol?
ans:
The path will be router A -> router D -> router E.

7. What is the purpose of the TTL field in the IP header?
ans:
limits the time or hops that a packet can traverse through the network before it should be discarded

8. Which two conditions are most likely to cause a routing loop? (Choose two.)
ans:
inconsistent routing tables
incorrectly configured static routes

9. Refer to the exhibit. If all routers are using RIP, how many rounds of updates will occur before all routers know all networks?
ans:
3

10. The graphic shows a network that is configured to use RIP routing protocol. Router2 detects that the link to Router1 has gone down. It then advertises the network for this link with a hop count metric of 16. Which routing loop prevention mechanism is in effect?
ans:
route poisoning

11. Refer to the exhibit. The routers in this network are running RIP. Router A has not received an update from Router B in over three minutes. How will Router A respond?
ans:
The Invalid timer will mark the route as unusable if an update has not been received in 180 seconds.

12. What actions will occur after RouterA loses connectivity to network 114.125.16.0? (Choose two.)
ans:
RouterB will include network 123.92.76.0 and 136.125.85.0 in its update to RouterA.
Router C will learn of the loss of connectivity to network 114.125.16.0 from RouterB.

13. Three routers running a distance-vector routing protocol lost all power, including the battery backups. When the routers reload, what will happen?
ans:
They will send updates that include only directly connected routes to their directly connected neighbors.

14. Which statement is true regarding cisco’s RIP_JITTER variable?
ans:
It prevents the synchronization of routing updates by subtracting a random length of time ranging from 0% to 15% of the specified interval time from the next routing update interval.

15. Which of the following methods does split horizon use to reduce incorrect routing information?
ans:
Information learned from one source is not distributed back to that source.

16. A network administrator is evaluating RIP versus EIGRP for a new network. The network will be sensitive to congestion and must respond quickly to topology changes. What are two good reasons to choose EIGRP instead of RIP in this case? (Choose two.)
ans:
EIGRP only updates affected neighbors.
EIGRP updates are partial.

17. Which two statements describe EIGRP? (Choose two.)
ans:
EIGRP sends triggered updates whenever there is a change in topology that influences the routing information.
EIGRP sends a partial routing table update, which includes just routes that have been changed.

18. Which three routing protocols are distance vector routing protocols? (Choose three).
ans:
RIPv1
EIGRP
RIPv2

19. Which of the following statements are correct about RIP?
ans:
will send out an update if there is a failure of a link

20. Which event will cause a triggered update?
ans:
a route is installed in the routing table