CCIE Routing and Switching FAQ: EIGRP

ccie-routing-switching-faq-eigrp

CCIE Routing and Switching FAQ: EIGRP

Q1. Which of the following items are true of EIGRP?
A. Authentication can be done using MD5 or clear text.
B. Uses UDP port 88.
C. Sends full or partial updates as needed.
D. Multicasts updates to 224.0.0.10 or FF02::A.

Answer: C and D

Q2. What classic metric components can be used by EIGRP for metric computation and best path selection?
A. Bandwidth
B. Cost
C. Delay
D. Hop count
E. Load
F. Expense
G. MTU
H. Reliability

Answer: A, C, E, and H

Q3. Which of the following accurately describe the manipulation with the component metrics?
A. Reliability is maximized.
B. Delay is summed.
C. Load is minimized.
D. Reliability is minimized.
E. Bandwidth is summed.
F. Load is maximized.
G. Bandwidth is minimized.

Answer: B, D, F, and G

Q4. Which statement is true regarding EIGRP’s use of Reliability and Load metric components on regular interfaces such as Ethernet or PPP?
A. EIGRP sends updates and recalculates the composite metric immediately whenever the Reliability and Load values on an interface change, regardless of K-value settings.

B. EIGRP sends updates and recalculates the composite metric immediately whenever the Reliability and Load values on an interface change but only when K-values are configured to take these components into account.

C. EIGRP samples the Reliability and Load in regular intervals and sends updates along with recalculating the composite metric when the sampled Reliability and Load values change.

D. EIGRP takes a snapshot of the interface Reliability and Load values in the moment of advertising a network, but changes to their values do not trigger sending further updates.

Answer: D

Q5. What are the shortcomings solved by Wide Metrics?
A. Gradual loss of resolution caused by repetitive descaling and scaling of Bandwidth and Delay components in integer arithmetics

B. Inability to use Reliability and Load without incurring routing table instabilities

C. Loss of resolution for interfaces with speeds over 1 Gbps

D. Inability to extend the metrics with additional future factors

Answer: A, C, and D

Q6. What are the component metrics used in Wide Metrics that can be used for best path selection?
A. Throughput
B. Latency
C. Reliability
D. Load
E. MTU
F. Hop Count
G. Extended Metrics

Answer: A, B, C, D, and G

Q7. Which of the following EIGRP packets are considered reliable packets?
A. Hello
B. Ack
C. Update
D. Query
E. Reply
F. SIA-Query
G. SIA-Reply

Answer: C, D, E, F, and G

Q8. Which of the following EIGRP packets can be sent as multicasts?
A. Hello
B. Ack
C. Update
D. Query
E. Reply
F. SIA-Query
G. SIA-Reply

Answer: A, C, and D

Q9. Which statements are true about Hello packets?
A. Hello packets must be confirmed.

B. Hello packets sent by a router contain a list of all detected neighbors on the interface.

C. Hello packets are usually sent as multicasts.

D. Default interval between Hello packets is 5 seconds on all interfaces.

E. Hello packets do not contain routing information.

Answer: C and E

Q10. Which EIGRP packet types are acknowledged?
A. Hello
B. Ack
C. Update
D. Query
E. Reply
F. SIA-Query
G. SIA-Reply

Answer: C, D, E, F, and G

Q11. Which EIGRP packet types can themselves act as acknowledgments?
A. Hello
B. Ack
C. Update
D. Query
E. Reply
F. SIA-Query
G. SIA-Reply

Answer: A, B, C, D, E, F, and G

Q12. What is the Computed Distance for a destination?
A. The current total distance to the destination computed over a particular neighbor router

B. The lowest known distance to the destination since the last time the destination transitioned from Active to Passive state

C. The current distance of a particular neighbor to the destination

D. The lowest known distance of a particular neighbor to the destination since the last time the destination transitioned from Active to Passive state

Answer: A

Q13. How many Computed Distances for a destination exist?
A. Only one, not bound to any particular neighbor
B. One per each neighbor that advertises the destination
C. One per each Successor
D. One per each Feasible Successor

Answer: B

Q14. What is the Reported Distance for a destination?
A. The current total distance to the destination computed over a particular neighbor router

B. The lowest known distance to the destination since the last time the destination transitioned from Active to Passive state

C. The current distance of a particular neighbor to the destination

D. The lowest known distance of a particular neighbor to the destination since the last time the destination transitioned from Active to Passive state

Answer: C

Q15. How many Reported Distances for a destination exist?
A. Only one, not bound to any particular neighbor
B. One per each neighbor that advertises the destination
C. One per each Successor
D. One per each Feasible Successor

Answer: B

Q16. What is the Feasible Distance for a destination?
A. The current total distance to the destination computed over a particular neighbor router

B. The lowest known distance to the destination since the last time the destination transitioned from Active to Passive state

C. The current distance of a particular neighbor to the destination

D. The lowest known distance of a particular neighbor to the destination since the last time the destination transitioned from Active to Passive state

Answer: B

Q17. How many Feasible Distances for a destination exist?
A. Only one, not bound to any particular neighbor
B. One per each neighbor that advertises the destination
C. One per each Successor
D. One per each Feasible Successor

Answer: A

Q18. Which statement correctly constitutes the Feasibility Condition in EIGRP?
A. The neighbor must be closer to the destination than I have ever been since the last time the destination became Passive .

B. The neighbor must be closer to the destination than I am .

C. The neighbor must be farther from the destination than I am .

D. The neighbor must be farther from the destination than I have ever been .

Answer: A

Q19. What statements correctly apply to a Successor?
A. It is a route over a particular neighbor.

B. It is a particular neighbor.

C. It must provide a loop-free path.

D. The Computed Distance over the Successor must be the lowest available.

E. The Computed Distance over the Successor does not need to be the lowest available.

F. In a connected network, there is always at least one Successor to a destination.

Answer: B, C, D, and F

Q20. What statements correctly apply to a Feasible Successor?
A. It is a route over a particular neighbor.

B. It is a particular neighbor.

C. It must provide a loop-free path.

D. The Computed Distance over the Feasible Successor must be the lowest available.

E. The Computed Distance over the Feasible Successor does not need to be the lowest available.

F. There is always at least one Feasible Successor to a destination.

Answer: B, C, and E

Q21. What is a local computation?
A. The process of local processing of all received Updates and Replies

B. The process of reevaluating and possibly changing a next hop to a destination locally that does not require the router to send Queries and wait for Replies before making its own decision

C. The process of computing the composite metric from individual components

D. The process of coordinating a change in the next hop to a destination by sending out Queries and waiting for Replies before making its own next-hop selection

Answer: B

Q22. What is a diffusing computation?
A. The process of local processing of all received Updates and Replies

B. The process of reevaluating and possibly changing a next hop to a destination locally that does not require the router to send Queries and wait for Replies before making its own decision

C. The process of computing the composite metric from individual components

D. The process of coordinating a change in the next hop to a destination by sending out Queries and waiting for Replies before making its own next-hop selection

Answer: D

Q23. Is the following statement true? “If a router has a Feasible Successor for a destination identified in its topology table, it will always be used in place of the current Successor if the Successor fails.”
A. Yes
B. No

Answer: B

Q24. How long at most will a diffusing computation run by default on a router before being terminated forcibly?
A. Indefinitely

B. 3 minutes

C. 3 minutes if the SIA-Query and SIA-Reply messages are not supported; 6 minutes if the SIA-Query and SIA Reply are supported

D. 15 seconds

Answer: C

Q25. What are some of the factors contributing to the occurrence of SIA states?
A. The use of route filtering and summarization
B. Excessive redundancy in the network
C. The use of the EIGRP Stub feature
D. Excessive network diameter
E. Large amount of routing information
F. The use of the EIGRP Add-Path feature

Answer: B, D, and E

Q26. What statements are true about running EIGRP Named Mode?
A. Verbal names of EIGRP processes on neighboring routers must match for the routers to establish adjacencies.

B. Multiple autonomous system instances for a single address family can be run in a single EIGRP named process.

C. Multiple autonomous system instances for different address families can be run in a single EIGRP named process.

D. Both classic and named mode can be used on a router as long as they do not conflict on the address family and the autonomous system number.

E. The use of named mode still permits that per-interface commands can be applied to interfaces to maintain backward compatibility.

F. The named mode contains a superset of all commands from the classic mode.

Answer: C, D, and F

Q27. What statements are true about EIGRP RID?
A. EIGRP has no concept of a RID.

B. The RID is equal to the autonomous system number.

C. The RID is advertised with all external and, in recent IOS releases, also with all internal routes.

D. The RID indicates the immediate neighbor advertising a route.

E. The RID indicates the originator of the routing information.

Answer: C and E

Q28. What statements are true about unequal cost load balancing in EIGRP?
A. Feasible Successors are required for this feature.

B. Multiple unequal cost paths can be advertised by a router to its neighbors.

C. Each unequal-cost path will be assigned a share of traffic in inverse proportion to how many times worse it is than the current best path.

D. EIGRP allows using any worse-cost path as long as the neighbor advertising this path is closer to the destination than this router.

Answer: A and C

Q29. What statements are true about the EIGRP Stub Router feature?
A. No Queries are sent by a stub router.

B. No Queries are usually sent to a stub router.

C. All Queries sent to a stub router are responded to by Replies indicating unreachability.

D. Depending on what routes the stub router is allowed to advertise, some Queries can be responded to normally while others will elicit a Reply indicating unreachability.

E. Neighbors of a stub router must be configured to treat that router as a stub.

F. A router is capable of advertising itself as a stub.

Answer: B, D, and F

Q30. What statements are true about EIGRP authentication?
A. In recent IOS versions, SHA-2 with 256-bit digests is supported.
B. MD5 digest is always supported.
C. Key chains or passwords can be used for SHA-2 authentication.
D. Key chains or passwords can be used for MD5 authentication.
E. IPv6 EIGRP uses IPsec for authentication purposes.

Answer: A, B, and C

Q31. What of the following are true regarding the default route injection into EIGRP?
A. Thenetwork 0.0.0.0 command is the preferred way of injecting the default route into EIGRP.

B. A default route can be injected into EIGRP by redistribution.

C. A default route can be injected into EIGRP by summarization.

D. Neighbors of stub routers send a default route to stub routers automatically

Answer: B and C

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