Cisco Catalyst 3750 Software Configuration Manual page 501

Chapter 26 Configuring QoS
Understanding Hierarchical QoS
• VLAN level—You start configuration of per-VLAN QoS by entering the match vlan vlan-id
class-map configuration command on one or more VLANs or by entering the match vlan vlan-id
and the match vlan inner vlan-id class-map configuration command on one or more 802.1Q
tunnels. At this level, you can configure the VLANs or 802.1Q tunnels to police, to share the
available port bandwidth and to enable CBWFQ, and to shape the traffic. You configure these
features by using the police cir, police cir percent, bandwidth, and shape policy-map class
configuration commands.
For a finer level of control, you also can associate a previously defined child policy at the class level
with a new service policy by using the service-policy policy-map class configuration command. In
the class-level child policy, you can configure tail drop or WRED drop policies, set Layer 2 and
Layer 3 QoS fields, or enable the priority queue. These features are available only at the class level.
By using a child policy, you apply a class-level policy only to traffic that matches the VLAN class.
You cannot mix VLAN-level and class-level matches within a class map.
You can attach up to 2045 user-created VLAN-level classes. This means that you can have 1022
unique classes and can associate them with the two ES ports (and have one left over), or you can add
more classes to one ES port and can subtract from the other one. You can shape every class that you
configure. You can create up to 4093 class maps.
This is an example of a VLAN-level classification and its naming convention:
Switch(config)# class-map match-all vlan-level-class-map-name
Switch(config-cmap)# match vlan 5
Switch(config-cmap)# match vlan inner 3 - 8
This is an example of a VLAN-level policy-map and its naming convention:
Switch(config)# policy-map vlan-level-policy-map-name
Switch(config-pmap)# class vlan-level-class-name
Switch(config-pmap-c)# police cir 500000 bc 10000 pir 1000000 be 10000 conform-action
transmit exceed-action set-prec-transmit 2 violate-action drop
This is an example of a VLAN-level policy-map and its naming convention when a previously
defined child policy is associated at the class level:
Switch(config)# policy-map vlan-level-policy-map-name
Switch(config-pmap)# class vlan-level-class-name
Switch(config-pmap-c)# bandwidth percent 30
Switch(config-pmap-c)# service-policy class-level-policy-map-name
This is a VLAN-level configuration example that combines a VLAN-level classification and a
VLAN-level policy-map:
Switch(config)# class-map match-all vlan203
Switch(config-cmap)# match vlan 203
Switch(config-cmap)# exit
Switch(config)# policy-map vlan-policy
Switch(config-pmap)# class vlan203
Switch(config-pmap-c)# police cir 500000 bc 10000 pir 1000000 be 10000 conform-action
transmit exceed-action set-prec-transmit 2 violate-action drop
Catalyst 3750 Metro Switch Software Configuration Guide
26-21
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