Where is the error in the following policy-map configuration?
policy-map test
class voice
priority 168
class mission-critical
bandwidth 192
random-detect
class class-default
fair-queue
bandwidth 128
A.
The bandwidth command is not a valid command for the class-default traffic class in this case.
B.
The voice traffic class is missing the random-detect command.
C.
The mission-critical traffic class bandwidth guarantee should be lower than the voice traffic class priority bandwidth guarantee.
D.
The mission-critical traffic class is missing the queue-limit command.
E.
Fair-queue should be enabled for the mission-critical traffic class.
Explanation:
The simplicity of configuration is made possible through the use of a common configuration structure for all QoS components within the MQC. That is, the basic configuration steps for configuring all QoS mechanisms is the same, with only small variations in the configuration that are specific to the actual mechanism. You can configure all the mechanisms through a three-step process:
Step 1. Class map configuration
Step 2. Policy map configuration
Step 3. Service policy applicationThe Class-map
The first step for configuring any QoS mechanism in the MQC is the configuration of a class-map. Simply stated, the class map defines which traffic you want the router to match. This is the fundamental step that allows the router to differentiate one traffic type from another. This is traffic classification, and without classification there can be no QoS. To differentiate traffic, it is possible to match on one traffic characteristic or multiple characteristics. If you need to differentiate between traffic from 10.1.1.1 and traffic from 10.1.1.2, for example, the source IP address is the only characteristic that you need to configure. If you have multiple traffic streams from 10.1.1.1 and need to differentiate between those, however, as well as differentiate between multiple streams from 10.1.1.2, you probably need to classify traffic based on multiple criteria, such as TCP or UDP port.
A possible scenario in which this would come into play might be server 10.1.1.1 that serves production HTTP and FTP to the Accounting department, and server 10.1.1.2 that serves nonproduction HTTP and FTP to the IT group that develops applications for the Accounting department. Understanding that production traffic is the top priority, the development group needs their traffic to have a minimum bandwidth guarantee to enable that group to properly test a new HTTP application before delivering it to the Accounting department for production use. This means that there will be QoS requirements for all traffic from 10.1.1.1 and some traffic from 10.1.1.2. As such, just matching by IP address does not suffice. In this case, there is a requirement to match on multiple characteristics.
Example of Creating class-map
R1(config)# class-map ?
WORD class-map name
match-all Logical-AND all matching statements under this classmap match-any Logical-OR all matching statements under this classmap
Please note this is no longer valid since, with the come of HQF, you can specify a bandwidth value even in the class-default class.