Reference Guide

Quality of Service (QoS) | 429
Mapping dot1p Values to Service Queues
All traffic is, by default, mapped to the same queue, Queue 0. If you honor dot1p on ingress, you can create
service classes based the queueing strategy in Table 24-4 using the
service-class dynamic dot1p command
from INTERFACE mode. Apply this queuing strategy globally by entering this command from
CONFIGURATION mode.
• All dot1p traffic is mapped to Queue 0 unless you enable the
service-class dynamic dot1p command on
an interface or globally.
• Layer 2 or Layer 3 service policies supersede dot1p service classes.
Guaranteeing Bandwidth to dot1p-Based Service Queues
To guarantee a minimum bandwidth to queues globally from CONFIGURATION mode, use the
service-class bandwidth-weight command. The command is applied in the same way as the bandwidth-weight
command in an output QoS policy (refer to Allocate Bandwidth to the Queue). The
bandwidth-percentage
command in QOS-POLICY-OUT mode supersedes the
service-class bandwidth-weight command.
Apply an Input Policy Map to an Interface
To apply an input policy map to an interface, use the service-policy input command from INTERFACE
mode. Specify the keyword
layer2 if the policy map you are applying is a Layer 2 policy map; in this case,
the INTERFACE must be in Switchport mode. You can apply the same policy map to multiple interfaces,
and you can modify a policy map after you apply it.
• You cannot apply an input Layer 2 QoS policy on an interface you also configure with the
vlan-stack
ac
cess command.
• If you apply a service policy that contains an ACL to more than one interface, FTOS uses ACL
optimization to conserves CAM space. (See CAM Optimization for details)
Create Output Policy Maps
1. To create an output policy map, use the policy-map-output command from CONFIGURATION mode.
2. After you create an output policy map, do one or more of the following:
• Apply an Output QoS Policy to a Queue
• Specify an Aggregate QoS Policy
• Apply an Output Policy Map to an Interface
3. Apply the policy map to an interface.
Apply an Output QoS Policy to a Queue
To apply an output QoS policy to queues, use the service-queue command from INTERFACE mode.
Specify an Aggregate QoS Policy
To specify an aggregate QoS policy, use the policy-aggregate command from POLICY-MAP-OUT mode.