Q&A
The questions and scenarios in this book are designed to be challenging and to make sure that you know the answer. Rather than allowing you to derive the answers from clues hidden inside the questions themselves, the questions challenge your understanding and recall of the subject.
You can find the answers to these questions in Appendix A. For more practice with exam-like question formats, use the exam engine on the CD-ROM.
| 1. | In a totally stubby area, which routes are not propagated into the area? |
| 2. | Can a virtual link transit a stub area? |
| 3. | An ABR must be resident in which area? |
| 4. | What LSAs will the ABR forward? |
| 5. | State two advantages in creating areas in OSPF. |
| 6. | What is an external route, and on which type of router will this route be introduced? |
| 7. | Why is the use of summarization important in the design of OSPF? |
| 8. | What is an estimate of the maximum number of routers that should reside in a given area? |
| 9. | What restrictions govern the creation of a stub or totally stubby area? |
| 10. | A virtual link in OSPF is used to solve what problem? |
| 11. | What issues may emerge when running OSPF within an area containing a Frame Relay NBMA cloud? |
| 12. | State one advantage in making centralized routers and network resources reside in Area 0 while the Frame Relay cloud and stub remote LANs reside in satellite stub areas. |
| 13. | How does creating multiple areas in OSPF reduce the number of SPF calculations? |
| 14. | How does a stub area differ from the backbone area? |
| 15. | How does a totally stubby area differ from a stub area? |
| 16. | State the different LSA types. |
| 17. | Where does the backbone router reside, and what is its function? |
| 18. | There are two types of summarization. What are they? |
| 19. | Which router type creates LSA Types 3 and 4? |
| 20. | Which command in OSPF shows the network LSA information? |
| 21. | What command would you use to create a totally stubby area? |
| 22. | What is a virtual link, and which command would you use to create it? |
| 23. | Where would you issue the command to summarize IP subnets? State the command that is used. |
| 24. | How would you summarize external routes before injecting them into the OSPF domain? |
| 25. | Give the command for defining the cost of a default route propagated into an area. |
| 26. | Give an example of when it would be appropriate to define a default cost. |
| 27. | On which router is the area default cost defined? |
| 28. | Give the command to configure a stub area and state on which router it is configured. |
| 29. | What is the purpose of the area range command, and why is it configured on the ABR? |
| 30. | Give the commands to configure a router to place subnets 144.111.248.0 through to 144.111.255.0 in Area 1 and to put all other interfaces into Area 0. |
| 31. | Give the syntax to summarize the external subnets 144.111.248.0 to 144.111.254.255 into OSPF. |
| 32. | Explain (briefly) the difference between the area range command and the summary-address command. |
| 33. | Explain the following syntax and what it will achieve: area 1 stub no-summary. |
| 34. | Why would you configure the routing process to log adjacency changes as opposed to turning on debug for the same trigger? |
| 35. | Give some of the common reasons that neighbors fail to form an adjacency. |
| 36. | When configuring a virtual link, which routers are configured? |
| 37. | What does the command area 1 default-cost 15 achieve? |
| 38. | Explain what is placed in the parameters area-id and router-id for the command area area-id virtual-link router-id. |
