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Catalyst 3560 Switch Software Configuration Guide
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Configuring QoS
This chapter describes how to configure quality of service (QoS) by using automatic QoS (auto-QoS)
commands or by using standard QoS commands on the Catalyst 3560 switch. With QoS, you can provide
preferential treatment to certain types of traffic at the expense of others. Without QoS, the switch offers
best-effort service to each packet, regardless of the packet contents or size. It sends the packets without
any assurance of reliability, delay bounds, or throughput.
In software releases earlier than Cisco IOS Release 12.2(25)SE, you can configure QoS only on physical
ports. In Cisco IOS Release 12.2(25)SE or later, you can configure QoS on physical ports and on switch
virtual interfaces (SVIs). Other than to apply policy maps, you configure the QoS settings, such as
classification, queueing, and scheduling, the same way on physical ports and SVIs. When configuring
QoS on a physical port, you apply a nonhierarchical policy map to a port. When configuring QoS on an
SVI, you apply a nonhierarchical or a hierarchical policy map. In the Catalyst 3750 Metro switch
documentation, nonhierarchical policy maps are referred to as nonhierarchical single-level policy maps,
and hierarchical policy maps are referred to as hierarchical dual-level policy maps.
Note For complete syntax and usage information for the commands used in this chapter, see the command
reference for this release.
This chapter consists of these sections:
Understanding QoS, page 34-2
Configuring Auto-QoS, page 34-20
Displaying Auto-QoS Information, page 34-29
Configuring Standard QoS, page 34-30
Displaying Standard QoS Information, page 34-78
The switch supports some of the modular QoS CLI (MQC) commands. For more information about the
MQC commands, see the “Modular Quality of Service Command-Line Interface Overview” at this site:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter0918
6a00800bd908.html