CCNA 3 Chapter 7: EIGRP Tuning and Troubleshooting (v5.0.3 + v6.0) Exam Answers – 100% Result

Certification Answers

Q1. In which scenario will the use of EIGRP automatic summarization cause inconsistent routing in a network?

  • when the routers in an IPv4 network have mismatching EIGRP AS numbers
  • when the routers in an IPv4 network are connected to discontiguous networks with automatic summarization enabled
  • when there is no adjacency that is established between neighboring routers
  • when there is no common subnet that exists between neighboring routers
Explanation:  If there are discontiguous IPv4 networks, automatic summarization causes inconsistent routing because routes are summarized at classful boundaries. When there is no common subnet between EIGRP neighbors, an adjacency cannot form. Mismatching EIGRP AS numbers and the lack of an adjacency will not cause inconsistent routing, but a lack of routing overall.

Q2. What is the purpose of a Null0 route in the routing table?

  • to prevent routing loops
  • to redistribute external routes into EIGRP
  • to act as a gateway of last resort
  • to prevent the router from sending EIGRP packets
Explanation:  EIGRP for IPv4 automatically installs a Null0 summary route into the routing table when EIGRP automatic summarization is enabled and there is at least one EIGRP learned subnet. Null0 is a virtual interface that is a route to nowhere and is used to prevent routing loops for destinations that are included in a summary network but do not have a specific entry in the routing table.

Q3. Question

Explanation:  No answer description available for this question

Q4. Fill in the blank. Do not use abbreviations.

The passive-interface command causes an EIGRP router to stop sending hello packets through an interface
Explanation:  The passive-interface command prevents routing updates and hello packets from traveling through an interface.

Q5. Question

Explanation:  No answer description available for this question

Q6. By default, how many equal-cost routes to the same destination network will EIGRP install in the routing table?

  • 2
  • 4
  • 6
  • 8
Explanation:  For load balancing, EIGRP will by default install up to four equal-cost paths to the same destination network in the routing table.

Q7. Open the PT Activity. Perform the tasks in the activity instructions and then answer the question. R1 and R2 could not establish an EIGRP adjacency. What is the problem?

  • EIGRP is down on R2.
  • R1 Fa0/0 link local address is wrong.
  • EIGRP is down on R1.
  • R1 Fa0/0 is not configured to send hello packets.
  • R1 Fa0/0 and R2 Fa0/0 are on different networks.
Explanation:  The IPv6 EIGRP process is down on R1 as can be seen:
R1# show ipv6 eigrp interfaces
IPv6-EIGRP interfaces for process 1
% EIGRP 1 is in SHUTDOWN
R1#
The administrator must issue the no shutdown command on the IPv6 router configuration mode.

Q8. Question

Explanation:  No answer description available for this question

Q9. Which three statements are advantages of using automatic summarization? (Choose three.)

  • It maximizes the number of routes in the routing table.
  • It decreases the number of entries in the routing table.
  • It reduces the frequency of routing updates.
  • It ensures that traffic for multiple subnets uses one path through the internetwork.
  • It improves reachability in discontiguous networks.
  • It increases the size of routing updates.
Explanation:  Automatic summarization minimizes the number of routes in the routing table. It reduces the frequency of routing updates. A disadvantage of automatic summarization is that it can create reachability problems in discontiguous networks.

Q10. Question

Explanation:  No answer description available for this question

Q11. What is the administrative distance of externally learned EIGRP routes?

  • 170
  • 120
  • 110
  • 90
Explanation:  There are multiple administrative distances assigned to EIGRP routes. An administrative distance of 170 is used for external EIGRP routes, which could be routes learned from another routing protocol and redistributed into EIGRP.

Q12. Which routing protocol supports unequal-cost load balancing on Cisco routers?

  • OSPF
  • IS-IS
  • RIPv2
  • EIGRP
Explanation:  EIGRP is unique because of its support of unequal-cost load balancing.

Q13. Question

Explanation:  No answer description available for this question

Q14. Which two steps must be taken in order to send a default route to other EIGRP routers? (Choose two.)

  • Configure a loopback address.
  • Configure a default route.
  • Configure a router ID.
  • Ensure automatic summarization is disabled.
  • Redistribute the default route.
Explanation:  Any router can have a default route (quad zero route) configured. In order to propagate a default route down to other EIGRP routers, the redistribute static command is used to include the configured default route in EIGRP updates.

Q15. Question

Explanation:  No answer description available for this question

Q16. Question

Explanation:  No answer description available for this question

Q17. Question

Explanation:  No answer description available for this question

Q18. When a Cisco router is configured with a fast-switching, how are packets distributed over equal-cost paths?

  • on a per-packet basis
  • on a per-interface basis
  • on a per-path-load basis
  • on a per-destination basis
Explanation:  In Cisco IOS, when packets are fast-switched, load balancing over equal-cost paths occurs on a per-destination basis.

Q19. What is the default maximum amount of bandwidth that can be used for exchanging EIGRP messages on an EIGRP-configured interface?

  • 50%
  • 10%
  • 100%
  • 75%
Explanation:  By default, EIGRP uses up to 50% of the configured bandwidth of an interface for EIGRP control information. On a 128 kbps link, this would mean that up to 64 kbps is used for EIGRP information.

Q20. Fill in the blank. Do not use abbreviations.

The command to propagate the default route from the router Border to the rest of the EIGRP domain is Border(config-router)# redistribute static
Explanation:  One way to propagate the default route to the rest of the EIGRP domain is to use the command redistribute static in the router eigrp (config-router)# mode.

Q21. Question

Explanation:  No answer description available for this question

Q22. Which command can be issued on a router to verify that automatic summarization is enabled?

  • show ip protocols
  • show ip eigrp neighbors
  • show ip eigrp interfaces
  • show ip interface brief
Explanation:  To verify if automatic summarization is being performed on a router, issue the show ip protocols command. The show ip eigrp interfaces command shows which interfaces are enabled for EIGRP. The show ip interface brief command is used to verify that the status and protocol are both up for an interface connected to a router. The show ip eigrp neighbors command on a router verifies the establishment of EIGRP neighbor adjacencies with other routers.

Q23. Question

Explanation:  No answer description available for this question

Q24. When a Cisco router is configured with fast-switching, how are packets distributed over equal-cost paths?

  • on a per-packet basis.
  • on a per-destination basis
  • on a per-interface basis
  • on a per-path-load basis
Explanation:  In Cisco IOS, when packets are fast-switched, load balancing over equal-cost paths occurs on a per-destination basis.

Q25. Which verification command would identify the specific interfaces on a router that were configured with the passive-interface command?

  • show ip protocols
  • show ip route eigrp
  • show ip eigrp neighbors
  • show ip interface brief
Explanation:  The show ip protocols command will identify interfaces that are configured as passive.

Q26. What is the administrative distance of a static route that has been redistributed into EIGRP?

  • 5
  • 20
  • 90
  • 170
Explanation:  Whereas internal EIGRP routes have an administrative distance of 90, redistributed routes, including redistributed static routes, have an administrative distance of 170.

Q27. Two routers, R1 and R2, share a 64 kb/s link. An administrator wants to limit the bandwidth used by EIGRP between these two routers to 48 kb/s. Which command is used on both routers to configure the new bandwidth setting?

  • ip bandwidth-percent eigrp 64 48
  • ip bandwidth-percent eigrp 75 100
  • ip bandwidth-percent eigrp 100 75
  • ip bandwidth-percent eigrp 100 48
  • ip bandwidth-percent eigrp 100 64
Explanation:  If two routers share a link of 64 kb/s and the administrator wants to limit the bandwidth used by EIGRP between these two routers to 48 kb/s, then this value corresponds to 75% of the link bandwidth. So, the command to be issued on both routers is ip bandwidth-percent eigrp 100 75.

Q28. Question

Explanation:  No answer description available for this question

Q29. Which protocol is used by EIGRP to send hello packets?

  • TCP
  • UDP
  • RTP
  • IP
Explanation:  No answer description available for this question

Q30. When an EIGRP-enabled router uses a password to accept routes from other EIGRP-enabled routers, which mechanism is used?

  • bounded updates
  • partial updates
  • EIGRP authentication
  • Diffusing Update Algorithm
  • Reliable Transport Protocol
Explanation:  No answer description available for this question

Q31. What is the purpose of using protocol-dependent modules in EIGRP?

  • to describe different routing processes
  • to identify different application layer protocols
  • to use different transport protocols for different packets
  • to accommodate routing of different network layer protocols
Explanation:  No answer description available for this question

Q32. If all router Ethernet interfaces in an EIGRP network are configured with the default EIGRP timers, how long will a router wait by default to receive an EIGRP packet from its neighbor before declaring the neighbor unreachable?

  • 10 seconds
  • 15 seconds
  • 20 seconds
  • 30 seconds
Explanation:  No answer description available for this question

Q33. Which statement describes a characteristic of the delivery of EIGRP update packets?

  • EIGRP uses UDP to send all update packets.
  • EIGRP sends all update packets via unicast.
  • EIGRP sends all update packets via multicast.
  • EIGRP uses a reliable delivery protocol to send all update packets.
Explanation:  No answer description available for this question

Q34. Which destination MAC address is used when a multicast EIGRP packet is encapsulated into an Ethernet frame?

  • 01-00-5E-00-00-09
  • 01-00-5E-00-00-10
  • 01-00-5E-00-00-0A
  • 01-00-5E-00-00-0B
Explanation:  No answer description available for this question

Q35. Why would a network administrator use a wildcard mask in the network command when configuring a router to use EIGRP?

  • to lower the router overhead
  • to send a manual summarization
  • to exclude some interfaces from the EIGRP process
  • to subnet at the time of the configuration
Explanation:  No answer description available for this question

Q36. Question

Explanation:  No answer description available for this question

Q37. Which EIGRP route would have the preferred administrative distance?

  • a summary route
  • an internal route
  • an external route that is redistributed from RIP
  • an external route that is redistributed from OSPF
Explanation:  No answer description available for this question

Q38. Where are EIGRP successor routes stored?

  • only in the routing table
  • only in the neighbor table
  • in the routing table and the topology table
  • in the routing table and the neighbor table
Explanation:  No answer description available for this question

Q39. Which table is used by EIGRP to store all routes that are learned from EIGRP neighbors?

  • the routing table
  • the neighbor table
  • the topology table
  • the adjacency table
Explanation:  No answer description available for this question

Q40. How do EIGRP routers establish and maintain neighbor relationships?

  • by exchanging neighbor tables with directly attached routers
  • by comparing known routes to information received in updates
  • by exchanging hello packets with neighboring routers
  • by dynamically learning new routes from neighbors
  • by exchanging routing tables with directly attached routers
Explanation:  No answer description available for this question

Q41. Which command or commands must be entered on a serial interface of a Cisco router to restore the bandwidth to the default value of that specific router interface?

  • bandwidth 1500
  • shutdown
  • no shutdown
  • copy running-config startup-config
  • reload
  • no bandwidth
Explanation:  No answer description available for this question

Q42. Which command is used to display the bandwidth of an interface on an EIGRP-enabled router?

  • show ip route
  • show interfaces
  • show ip protocols
  • show ip interface brief
Explanation:  The privileged EXEC mode command show interfaces is used to verify the default or configured bandwidth value on an interface. Correct bandwidth values are important for efficient routing with EIGRP.

Q43. A new network administrator has been asked to verify the metrics that are used by EIGRP on a Cisco device. Which two EIGRP metrics are measured by using static values on a Cisco device? (Choose two.)

  • bandwidth
  • load
  • reliability
  • delay
  • MTU
Explanation:  No answer description available for this question

Q44. Which three metric weights are set to zero by default when costs in EIGRP are being calculated? (Choose three.)

  • k1
  • k2
  • k3
  • k4
  • k5
  • k6
Explanation:  No answer description available for this question

Q45. Question

Explanation:  No answer description available for this question

Q46. What is indicated when an EIGRP route is in the passive state?

  • The route has the highest path cost of all routes to that destination network.
  • The route must be confirmed by neighboring routers before it is put in the active state.
  • The route is a feasible successor and will be used if the active route fails.
  • There is no activity on the route to that network.
  • The route is viable and can be used to forward traffic.
Explanation:  Passive state means that the router topology table is stable and is converged.

Q47. Question

Explanation:  No answer description available for this question

Q48. Fill in the blank.

In an EIGRP topology table, a route that is in a/an active state will cause the Diffusing Update Algorithm to send EIGRP queries that ask other routers for a path to this network.
Explanation:  No answer description available for this question

Q49. Which two EIGRP packet types are sent with unreliable delivery? (Choose two.)

  • update
  • query
  • hello
  • reply
  • acknowledgment
Explanation:  No answer description available for this question

Q50. What is identified within the opcode of an EIGRP packet header?

  • the EIGRP message type that is being sent or received from a neighbor
  • the EIGRP autonomous system metrics
  • the EIGRP hold timer agreed upon with a neighbor
  • the EIGRP sum of delays from source to destination
Explanation:  No answer description available for this question

Q51. An administrator issues the router eigrp 100 command on a router. What is the number 100 used for?

  • as the autonomous system number
  • as the number of neighbors supported by this router
  • as the length of time this router will wait to hear hello packets from a neighbor
  • as the maximum bandwidth of the fastest interface on the router
Explanation:  No answer description available for this question

Q52. What information does EIGRP maintain within the routing table?

  • both successors and feasible successors
  • only feasible successors
  • adjacent neighbors
  • all routes known to the router
  • only successors
Explanation:  Only successor routes are offered to the routing table.

Q53. Question

Explanation:  No answer description available for this question

Q54. What is the multicast address used by an EIGRP-enabled router operating with IPv6?

  • FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF
  • FF02::A
  • FF02::B
  • FF02::1
Explanation:  The multicast address for EIGRP for IPv6 is FF02::A, which is the shortened form of FF02:0000:0000:0000:0000:0000:0000:A

Q55. Which configuration is necessary to ensure successful operation of EIGRP for IPv6?

  • The eigrp router-id command requires an IPv6 address within the router configuration mode.​
  • The network command is required within the router configuration mode.​
  • The no shutdown command is required within the router configuration mode.​
  • The router eigrp autonomous-system command is required within the router configuration mode.
Explanation:  No answer description available for this question

Q56. Fill in the Blank. Use the abbreviation.

EIGRP uses the RTP protocol to deliver EIGRP packets to neighbors.​
Explanation:  No answer description available for this question

Q57. Question

Explanation:  No answer description available for this question

Q58. Question

Explanation:  No answer description available for this question

Q59. Question

Explanation:  No answer description available for this question

Q60. Which two EIGRP packet types are sent with reliable delivery? (Choose two.)

  • update query
  • hello
  • acknowledgment
  • reply
Explanation:  No answer description available for this question