"Do I Know This Already?" Quiz Questions

The purpose of the "Do I Know This Already?" quiz is to help you decide whether you really need to read the entire chapter. If you already intend to read the entire chapter, you do not necessarily need to answer these questions now.

The 10-question quiz, derived from the major sections in "Foundation Topics" portion of the chapter, helps you determine how to spend your limited study time.

Table 4-1 outlines the major topics discussed in this chapter and the "Do I Know This Already?" quiz questions that correspond to those topics.

Table 4-1. "Do I Know This Already?" Foundation Topics Section-to-Question Mapping

Foundation Topics Section Covering These Questions	Questions	Score
Classification and Marking Concepts	14
Classification and Marking Tools	58
Classification Issues when Using VPNs	910
Total Score

You can find the answers to the "Do I Know This Already?" quiz in Appendix A, "Answers to the ' Do I Know this Already Quizzes and Q&A Sections." The suggested choices for your next step are as follows:

• 8 or less overall score Read the entire chapter. This includes the "Foundation Topics," the "Foundation Summary," and the "Q&A" sections.
  
  
• 9 or 10 overall score If you want more review on these topics, skip to the "Foundation Summary" section and then go to the "Q&A" section. Otherwise, move to the next chapter.
  
  

Classification and Marking Concepts Questions

1.	Which of the following tools can be used to classify packets generated on behalf of an application that uses static well-known TCP port numbers? CB Marking ECN NBAR Pre-classify
2.	Which of the following tools can be used to classify packets generated on behalf of an application that dynamically allocates the TCP ports numbers used by the application? CB Marking ECN NBAR Pre-classify
3.	Which of the following header fields are part of the IEEE 802.1Q header? DE User Priority QoS DSCP ToS
4.	Imagine a PC, connected to an IP phone via an Ethernet cable, with the IP phone connected to a 2950 switch. The switch is cabled to an access router, which in turn has Frame Relay connectivity to the central site. Assuming trunking issued between the IP phone and the switch, where is the recommended trust boundary for data coming from the PC towards the central site? PC Phone Switch Access router Frame Relay cloud

Classification and Marking Tools Questions

5.	Imagine a router configuration with several class-map commands, with a policy map referring to the service classes defined in the class-map commands. The policy map has been enabled for incoming packets on interface Fa0/1. What command would you look for in order to tell if Class Based Marking was in use, as opposed to some other MQC command? match match-all priority mark set
6.	Examine the following example of commands typed in configuration mode in order to create a class map. Assuming that the class fred command was used inside a policy map, and the policy map was enabled on an interface, which of the following would be true in regards to packets classified by the class map? Router(config)#class-map fred Router(config)#match ip dscp ef Router(config)#match ip dscp af31 Matches packets with both DSCP EF or AF31 Matches packets with either DSCP EF or AF31 Matches all packets that are neither EF or AF31 Matches no packets Matches packets with precedence values of 3 and 5
7.	Examine the following configuration snippet, and assume that all commands related to the class-map and all interface commands are shown. Which of the following answer best explains why the show command shows that class barney is not matching any packets? class-map dino match protocol rtp audio ! policy-map barney class dino set ip dscp ef ! interface fastethernet0/0 ip address 1.1.1.1 255.255.255.0 service-policy input barney There is no RTP audio traffic currently in the network You cannot enable CB Marking as an input function The show command only works when the mls enable counters interface subcommand is used The ip cef global command is required . The show policy-map interface fa0/0 command lists configuration information, but not packet counters
8.	Assume that a router is configured correctly so that voice payload packets are marked with DSCP value EF. Which of the following commands could have been used inside the policy-map to cause CB Marking to set that value? set ip dscp ef set ip dscp 46 set dscp ef set dscp 46 All of the above None of the above

Classification Issues when Using VPNs Questions

9.

Router A is the endpoint of an IPSEC VPN tunnel. Packets entering router A before being encrypted into the tunnel have been marked with meaningful DSCP values. What causes router A to copy the ToS byte from the original packet into the new VPN IP header? It works automatically, without any commands required The ip cef global command is needed The mls qos global command is needed The qos pre-classify global command is needed The qos pre-classify command is needed on the IPSEC crypto map

10.

Router A is the endpoint of an IPSEC VPN tunnel. Packets entering router A on interface fa 0/0 will be encrypted and then forwarded to a central site out interface S0/0. You want to enable CB Marking on egress packets on the serial0/0 interface, but you want to look at the fields in the IP, TCP, and UDP headers of the original packet, before encryption. What must be done to allow your policy map to work? It works automatically, without any commands required The ip cef global command is needed The mls qos global command is needed The qos pre-classify global command is needed The qos pre-classify command is needed on the IPSEC crypto map