- Preface
- New and Changed Information
- Overview
- Configuring Classification
- Configuring Policy Maps
- Configuring Marking
- Configuring QoS on the System
- Configuring QoS on Interfaces
- Configuring QoS on VLANs
- Configuring Queuing and Flow Control
- Configuring Ingress Policing
- Configuring ACL Logging
- Configuring FEX-Based ACL Classification
- QoS Configuration Examples
- Index
Contents
- Configuring QoS on VLANs
- Information About VLAN QoS
- Precedence of QoS Policies
- Example of Interface, System, and VLAN Policy Precedence
- Example of Interface and System QoS Policy Precedence
- Example of System and VLAN Policy Precedence
- Example of VLAN QoS and VACL Policy Precedence
- Limiting TCAM Entries for VLAN QoS
- Guidelines and Limitations for VLAN QoS
- Configuring VLAN QoS
- Configuring or Changing the Interface QoS TCAM Limit
- Removing the Interface QoS Limit from the TCAM
- Configuring a Service Policy on a VLAN
- Removing a Service Policy from a VLAN
- Verifying the VLAN QoS Configuration
- Feature History for VLAN QoS
Configuring QoS on VLANs
This chapter contains the following sections:
- Information About VLAN QoS
- Precedence of QoS Policies
- Limiting TCAM Entries for VLAN QoS
- Guidelines and Limitations for VLAN QoS
- Configuring VLAN QoS
- Verifying the VLAN QoS Configuration
- Feature History for VLAN QoS
Information About VLAN QoS
On Cisco Nexus devices, you can configure quality of service (QoS) policies for classification and marking on VLANs. The policies that you apply to a VLAN are applied to the traffic on the VLAN's Layer 2 and switch virtual interface (SVI) ports.
Precedence of QoS Policies
The marking requirements in a QoS policy determine its precedence. Interface QoS policies take the highest precedence, the VLAN QoS policies are next, and the System QoS policies have the lowest precedence.
However, if a VLAN is assigned both a VLAN QoS policy and a VLAN ACL (VACL), the VACL takes the highest precedence.
- Example of Interface, System, and VLAN Policy Precedence
- Example of Interface and System QoS Policy Precedence
- Example of System and VLAN Policy Precedence
- Example of VLAN QoS and VACL Policy Precedence
Example of Interface, System, and VLAN Policy Precedence
This example shows a configuration where the traffic on interface 1/1 with CoS 5 goes to qos-group 3. Traffic on the other interfaces with VLAN 10 and CoS 5 go to qos-group 4. Traffic on interfaces other than VLAN 10 and CoS 5 go to qos-group 5.
class-map type qos match-all cm1
match cos 5
policy-map type qos pm-ifc
class cm1
set qos-group 3
class class-default
policy-map type qos pm-vlan
class cm1
set qos-group 4
class class-default
policy-map type qos pm-sys
class cm1
set qos-group 5
class class-default
system qos
service-policy type qos input pm-sys
vlan configuration 10
service-policy type qos input pm-vlan
interface Ethernet1/1
service-policy type qos input pm-ifc
Example of Interface and System QoS Policy Precedence
This example shows a configuration where the traffic on interface 1/1 with CoS 5 goes to qos-group 3. Traffic on the other interfaces with CoS 5 go to qos-group 5.
class-map type qos match-all cm1
match cos 5
policy-map type qos pm-ifc
class cm1
set qos-group 3
class class-default
policy-map type qos pm-sys
class cm1
set qos-group 5
class class-default
system qos
service-policy type qos input pm-sys
interface Ethernet1/1
service-policy type qos input pm-ifc
Example of System and VLAN Policy Precedence
This example shows a configuration where the traffic on VLAN 10 with CoS 5 goes to qos-group 4. Traffic on the other VLANs with CoS 5 go to qos-group 5.
class-map type qos match-all cm1
match cos 5
policy-map type qos pm-vlan
class cm1
set qos-group 4
class class-default
policy-map type qos pm-sys
class cm1
set qos-group 5
class class-default
system qos
service-policy type qos input pm-sys
vlan configuration 10
service-policy type qos input pm-vlan
Example of VLAN QoS and VACL Policy Precedence
In this example, the packets with source IP address 10.10.10.1 are dropped. However, the other packets with VLAN 10 and CoS 5 go to qos-group 4.
ip access-list al1
10 permit ip 10.10.10.1/24 any
vlan access-map v-am1
match ip address al1
action drop
vlan filter v-am1 vlan-list 10
class-map type qos match-all cm1
match cos 5
policy-map type qos pm-vlan
class cm1
set qos-group 4
class class-default
vlan configuration 10
service-policy type qos input pm-vlan
Limiting TCAM Entries for VLAN QoS
The QoS TCAM region is shared by the interface QoS, system QoS, and VLAN QoS policies. You need to limit the number of TCAM entries for the interface QoS policies in order to define VLAN QoS policies. Use the hardware profile tcam feature interface-qos limit tcam-size to configure this limit.
Guidelines and Limitations for VLAN QoS
A VLAN must have at least one active member port for a service policy to be configured on. If a VLAN does not have at least one active member, and you configure a service policy on it, the configuration is accepted; however, the TCAM is not programmed.
If a VLAN is removed with the no vlan number command, the service policy that is configured on that VLAN is still present, but it is not active.
The TCAM must have enough free entries to configure the service policy on the VLAN.
A rollback might fail if the interface QoS limit is different in the running configuration than in the rollback configuration.
If a VLAN with a QoS policy is configured on an interface with no QoS policy, the show policy-map interface number command does not display the QoS policy configured on the VLAN.
Remove all interface QoS policies before changing the interface QoS limit.
Configuring VLAN QoS
Configuring or Changing the Interface QoS TCAM Limit
To configure the interface_qos_limit to a specific number, the QoS region of the TCAMs in all of the ASICs cannot have any interfaces policies configured beyond the offset of that number. For example, to configure the interface_qos_limit to 1000, the QoS regions of the TCAMs in all of the ASICs cannot have any interface policies configured beyond offset 1000.
This example shows how to set the interface QoS TCAM limit to 20 entries:
switch(config)# configure terminal switch(config)# hardware profile tcam feature interface-qos limit 20 switch(config)# show hardware profile tcam feature qos Feature Limit (number of tcam entries) ------------------------------------------------------ interface-qos 20 vlan-qos + global-qos 428 switch(config)# copy running-config startup-config
Removing the Interface QoS Limit from the TCAM
This example shows how to remove the interface QoS TCAM limit:
switch(config)# configure terminal switch(config)# show hardware profile tcam feature qos Feature Limit (number of tcam entries) ------------------------------------------------------ interface-qos 20 vlan-qos + global-qos 428 switch(config)# no hardware profile tcam feature interface-qos limit 20 switch(config)# copy running-config startup-config
Configuring a Service Policy on a VLAN
This example shows how to create a service policy and assign it to VLAN 10:
switch# configure terminal switch(config)# class-map type qos cm1 switch(config-cmap-qos)# match cos 5 switch(config-cmap-qos)# policy-map type qos pm-vlan switch(config-pmap-qos)# class cm1 switch(config-pmap-c-qos)# set qos-group 4 switch(config-pmap-c-qos)# exit switch(config-pmap-qos)# exit switch(config)# vlan configuration 10 switch(config-vlan-config)# service-policy type qos input pm-vlan switch(config-vlan-config)#
Removing a Service Policy from a VLAN
This example shows how to remove the pm-vlan policy map from VLAN 10:
swtich# configure terminal switch(config)# vlan configuration 10 switch(config-vlan-config)# no service-policy type qos input pm-vlan switch(config-vlan-config)# copy running-config startup-config
Verifying the VLAN QoS Configuration
Use one of the following commands to verify the configuration:
Command |
Purpose |
|---|---|
show policy-map vlan vlan-number |
Displays the QoS policies configured on the specified VLAN. |
show policy-map [name] |
Displays the policy maps defined on the switch. Optionally, you can display the named policy only. |
running-config ipqos |
Displays information about the running configuration for QoS. |
startup-config ipqos |
Displays information about the startup configuration for QoS. |
Feature History for VLAN QoS
Feature Name |
Release |
Feature Information |
|---|---|---|
VLAN QoS |
5.1(3)N2(1) |
This feature was introduced. |