As mentioned in the Introduction, you have two choices for review questions. The questions that follow next give you a more difficult challenge than the exam itself by using an open-ended question format. By reviewing now with this more difficult question format, you can exercise your memory better, and prove your conceptual and factual knowledge of this chapter. You can find the answers to these questions in Appendix A.
The second option for practice questions is to use the CD-ROM included with this book. It includes a testing engine and more than 200 multiple-choice questions. You should use this CD-ROM nearer to the end of your preparation, for practice with the actual exam format. You can even customize the CD-ROM exam to include, or not include, the topics that are only on the CCIP QoS.
| 1. | Describe the difference between classification and marking. |
| 2. | Describe, in general, how a queuing feature could take advantage of the work performed by a classification and marking feature. |
| 3. | Characterize what must be true before the CoS field may be useful for marking packets. |
| 4. | Most other QoS tools, besides classification and marking tools, also have a classification feature. Describe the advantage of classification, in terms of overall QoS design and policies, and explain why classification and marking is useful, in spite of the fact that other tools also classify the traffic. |
| 5. | Which of the following classification and marking tools can classify based on the contents of an HTTP URL: class-based marking (CB Marking), QoS Pre-classification, network-based application recognition (NBAR), or cos-to-dscp maps? |
| 6. | Describe the differences between IP extended ACLs as compared with NBAR for matching TCP and UDP port numbers. |
| 7. | Which of the following QoS marking fields are carried inside an 802.1Q header: QoS, CoS, DE, ToS byte, User Priority, ToS bits, CLP, Precedence, QoS Group, DSCP, MPLS Experimental, or DS? |
| 8. | Which of the following QoS marking fields are carried inside an IP header: QoS, CoS, DE, ToS byte, User Priority, ToS bits, CLP, Precedence, QoS Group, DSCP, or MPLS Experimental? |
| 9. | Which of the following QoS marking fields are never marked inside a frame that exits a router: QoS, CoS, DE, ToS byte, User Priority, ToS bits, CLP, Precedence, QoS Group, DSCP, MPLS Experimental, or DS? |
| 10. | Describe the goal of marking near the edge of a network in light of the meaning of the term "trust boundary." |
| 11. | What configuration command lists the classification details when configuring CB Marking? What configuration mode must you use to configure the command? What commands must you issue to place the configuration mode user into that mode? |
| 12. | What configuration command lists the marking details when configuring CB Marking? What configuration mode must you use to configure the command? What commands must you issue to place the configuration mode user into that mode? |
| 13. | What configuration command enables CB Marking? What configuration mode must you use to configure the command? What commands must you issue to place the configuration mode user into that mode? |
| 14. | Describe how you can mark multiple DSCP values with a single class map. How many can you match with a single command? |
| 15. | What configuration command lets you match RTP audio without also matching RTP video traffic? |
| 16. | Describe the process by which NBAR can be updated to support new protocols, without upgrading IOS. |
| 17. | What CB Marking command implies that a policy map requires NBAR in order to match packets? |
| 18. | What command enables NBAR on an interface for incoming packets? For outgoing packets? |
| 19. | Describe the reason why you might see multiple set commands inside a single service class in a policy map, and give one example. |
| 20. | Imagine you are supposed to update a router configuration. The current configuration includes a class-map that refers to ACL 101, which has 23 ACL clauses (separate access-list commands). How could you easily create a new class map that matches the traffic denied by the ACL? |
| 21. | A router is configred to create a VPN tunnel. Explain the required steps you must take to cause a router to copy the ToS byte of the original packet into the ToS byte of the new IP header used to encapsulate the packet. |
| 22. | A router is configred to create a VPN tunnel, with unencrypted packets entering interface Fa0/0, and the encrypted packets going over a link to the internet (S0/0). Assuming as many defaults as possible were taken, could a policy map for packets entering the router's FA0/0 interface examine the packet headers as originally created by the end user device? Why? |
| 23. | A router is configred to create a VPN tunnel, with unencrypted packets entering interface Fa0/0, and the encrypted packets going over a link to the internet (S0/0). Assuming as many defaults as possible were taken, could a policy map for packets exiting the router's S0/0 interface examine the packet headers as originally created by the end user device? Why or why not? |
| 24. | A router is configred to create a VPN tunnel, with unencrypted packets entering interface Fa0/0, and the encrypted packets going over a link to the Internet (S0/0). Assuming the qos pre-classify command was configured correctly, could a policy map for packets entering the router's FA0/0 interface examine the packet headers as originally created by the end user device? Why or why not? |
| 25. | Name the three configuration areas in which you might use the qos pre-classify command in order to enable pre-classification. |
