"Do I Know This Already?" Quiz

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

Table 6-1 outlines the major topics discussed in this chapter and the "Do I Know This Already?" quiz questions that correspond to those topics.

Table 6-1. "Do I Know This Already?" Foundation Topics Section-to-Question Mapping

Foundations Topics Section	Questions Covered in This Section	Score
Shaping and Policing Concepts	15
Configuring Class-Based Shaping	68
Configuring Class-Based Policing	912
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:

• 10 or less overall score Read the entire chapter. This includes the "Foundation Topics," the "Foundation Summary," and the "Q&A" sections.
  
  
• 11 or 12 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.
  
  

Shaping and Policing Concepts Questions

1.	How big is the token bucket used by CB Shaping when no excess bursting is configured? Bc bytes Bc + Be bytes Bc bits Bc + Be bits
2.	Which of the following are true about Policers in general, but not true about Shapers? Monitors traffic rates using concept of token bucket Can discard traffic that exceeds a defined traffic rate Can delay packets by queuing in order to avoid exceeding a traffic rate Can re-mark a packet
3.	If shaping was configured with a rate of 128Kbps, and a Bc of 3200, what value would be calculated for Tc? 125 ms 125 sec 25 ms 25 sec Shaping doesn't use a Tc Not enough information to tell
4.	With dual-rate policing, upon what value does the policer base the size of the token bucket associated with the second, higher policing rate? Bc Be CIR PIR Not based on any other valueit must be statically configured.
5.	With single-rate policing, with three possible actions configured, how does the policer replenish tokens into the excess token bucket? By filling Bc * Tc tokens into the first bucket each time interval, with spilled tokens refilling the excess token bucket. By refilling the first bucket, based on a pro-rated amount of Bc, with spilled tokens refilling the excess token bucket. By Be * Tc each time interval By putting a pro-rated amount of Be into the excess token bucket directly. By Be tokens each second

Configuring Class-Based Shaping

6.	Which of the following commands, when typed in the correct configuration mode, enables shaping at 128 kbps, with no excess burst? shape average 128000 8000 0 shape average 128 8000 0 shape average 128000 shape peak 128000 8000 0 shape peak 128 8000 0 0 shape peak 128000
7.	Examine the following configuration, noting the locations of the comments lines labeled "point 1", point 2", and so on. Assume that a correctly-configured policy map that implements CBWFQ, called queue-it, is also configured but not shown. In order to enable CBWFQ for the packets queued by CB Shaping, what command is required, and at what point in the configuration would the command be required? policy-map shape-question ! point 1 class class-default ! point 2 shape average 256000 5120 ! point 3 interface serial 0/0 ! point 4 service-policy output shape-question ! point 5 interface s0/0.1 point-to-point ! point 6 ip address 1.1.1.1 ! point 7 frame-relay interface-dlci 101 ! point 8 service-policy queue-it, at point 1 service-policy queue-it, at point 3 service-policy queue-it, at point 5 service-policy queue-it, at point 6 shape queue service-policy queue-it, at point 1 shape queue service-policy queue-it, at point 3 shape queue service-policy queue-it, at point 5 shape queue service-policy queue-it, at point 6
8.	Using the same configuration snippet as in the previous question, what command would list the calculated Tc value, and what would that value be? show policy-map, Tc = 125 ms show policy-map, Tc = 20 ms show policy-map, Tc = 10 ms show policy-map interface s0/0, Tc = 125 ms show policy-map interface s0/0, Tc = 20 ms show policy-map interface s0/0, Tc = 10 ms

Configuring Class-Based Policing

9.	Which of the following commands, when typed in the correct configuration mode, enables CB policing at 128 kbps, with no excess burst? police 128000 conform-action transmit exceed-action transmit violate-action discard police 128 conform-action transmit exceed-action transmit violate-action discard police 128000 conform-action transmit exceed-action discard police 128 conform-action transmit exceed-action discard police 128k conform-action transmit exceed-action discard
10.	Examine the following configuration. Which of the following commands would be required to change this configuration so that the policing function would be a dual-rate policer, with CIR of 256 kbps and double that for the peak rate? policy-map police-question class class-default police 256000 conform-action transmit exceed-action set-dscp-transmit af11 violate-action discard interface serial 0/0 service-policy input police-question interface s0/0.1 point-to-point ip address 1.1.1.1 frame-relay interface-dlci 101 Replace the existing police command with police cir 256000 Bc 4000 Be 4000 conform-action transmit exceed-action transmit violate-action drop Replace the existing police command with police cir 256000 pir 512000 conform-action transmit exceed-action set-dscp-transmit af11 violate-action drop Replace the existing police command with police 256000 512000 conform-action transmit exceed-action transmit violate-action drop Replace the existing police command with police cir 256000 pir 2x conform-action transmit exceed-action transmit violate-action drop
11.	In the previous question, none of the answers specified the settings for Bc and Be. What would CB policing calculate for Bc and Be when policing at rates of 256 kbps and 512 kbps with a dual-rate policing configuration? 4000 and 4000, respectively 4000 and 8000, respectively 32000 and 32000, respectively 32000 and 64000, respectively
12.	Examine the following configuration, which shows all commands pertinent to this question. Which of the following police commands would be required to enable single-rate policing at approximately 128 kbps, with the Bc set to cause Tc = 10ms? (Note that a comment line shows where the police command would be added to the configuration.) policy-map police-question2 class class-default ! police command goes here interface serial 0/0 service-policy input police-question2 interface s0/0.1 point-to-point ip address 1.1.1.1 frame-relay interface-dlci 101 police cir 128000 Bc 1280 conform-action transmit exceed-action transmit violate-action discard police cir percent 8 conform-action transmit exceed-action transmit violate-action discard police cir 128000 Tc 10 conform-action transmit exceed-action transmit violate-action discard police cir percent 8 Bc 10 ms conform-action transmit exceed-action transmit violate-action discard