Cisco Systems OL-4266-08 Configuring the Ingress LAN Port CoS Value

42-91

Cisco7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX

OL-4266-08

Chapter42 Configuring PFC QoS

Configuring PFCQo S

•The mls qos trust cos command enables CoS-based receive-queue drop thresholds. To avoid

dropping traffic because of inconsistent CoS values, configure ports with the mls qos trust cos

command only when the received traffic is ISL or 802.1Q frames carrying CoS values that you know

to be consistent with network policy.

•With Release 12.2(17b)SXA and later releases, you can configure IEEE8021.Q tunnel ports

configured with the mls qos trust cos command to use a mutated CoS value instead of the received

CoS value (“Configuring Ingress CoS Mutation on IEEE 802.1Q Tunnel Ports” section on

page 42-83).

•Use the no mls qos trust command to set the port state to untrusted.

This example shows how to configure Gigabit Ethernet port 1/1 with the trust cos keywords:

Router# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)# interface gigabitethernet 1/1

Router(config-if)# mls qos trust cos

Router(config-if)# end

Router#

This example shows how to verify the configuration:

Router# show queueing interface gigabitethernet 1/1 | include trust

Trust state: trust COS

Router#

Configuring the Ingress LAN Port CoS Value

Note Whether or not PFC QoS uses the CoS value applied with the mls qos cos command depends on the trust

state of the port and the trust state of the traffic received through the port. The mls qos cos command

does not configure the trust state of the port or the trust state of the traffic received through the port.

To use the CoS value applied with the mls qos cos command as the basis of internal DSCP:

•On a port that receives only untagged ingress traffic, configure the ingress port as trusted or

configure a trust CoS policy map that matches the ingress traffic.

•On a port that receives tagged ingress traffic, configure a trust CoS policy map that matches the

ingress traffic.

You can configure the CoS value that PFCQoS assigns to untagged frames from ingress LAN ports

configured as trusted and to all frames from ingress LAN ports configured as untrusted.

Contents

Main CHAPT ER Configuring PFC QoS Understanding How PFC QoS Works Port Types Supported by PFC QoS Overview Page Page Page Figure 42-4 PFC QoS Features and Component Overview Component Overview Ingress LAN Port PFC QoS Features These sections provide an overview of the ingress port QoS features: Flowchart of Ingress LAN Port PFC QoS Features Figure 42-5 shows how traffic flows through the ingress LAN port PFC QoS features. Port Trust Ingress Congestion Avoidance PFC and DFC QoS Features Supported Policy Feature Cards Supported Distributed Forwarding Cards PFC and DFC QoS Feature List and Flowchart Cisco7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX OL-4266-08 Chapter42 Con figuring PFC QoS Understanding How PFCQoS Works Figure 42-6 shows how traffic flows through the QoS features on the PFC and DFCs. Figure 42-6 QoS Features on the PFC and DFCs Ingress PFC QoS Egress PFC QoS Internal DSCP Values Port-Based PFC QoS and VLAN-Based PFCQoS PFC QoS Egress Port Features Flowchart of PFC QoS Egress LAN Port Features Egress CoS Values Egress DSCP Mutation with a PFC3 Egress ToS Byte Egress PFC QoS Interfaces Egress ACL Support for Remarked DSCP Marking on Egress OSM Ports Understanding Classification and Marking Classification and Marking at Trusted and Untrusted Ingress Ports Classification and Marking at Untrusted Ingress Ports Ingress Classification and Marking at Trusted Ports Classification and Marking at Ingress OSM Ports Classification and Marking on the PFC Using Service Policies and Policy Maps Classification and Marking on the MSFC Policers Overview of Policers Aggregate Policers Microflow Policers Understanding Port-Based Queue Types Ingress and Egress Buffers and Layer 2 CoS-Based Queues Page Ingress Queue Types C C S a Egress Queue Types Module to Queue Type Mappings Page PFC QoS Default Configuration PFC QoS Global Settings Default Values With PFC QoS Enabled Receive-Queue Limits Transmit-Queue Limit s Bandwidth Allocation Ratios Default Drop-Threshold Percentages and CoS Value Mappings 1q2t Receive Queues 1q4t Receive Queues 1p1q4t Receive Queues 1p1q0t Receive Queues 1p1q8t Receive Queues 1q8t Receive Queues 2q8t Receive Queues 8q4t Receive Queues Page Page Page 8q8t Receive Queues 2q2t Transmit Queues 1p2q2t Transmit Queues 1p3q8t Transmit Queues 1p7q4t Transmit Queues Page Page 1p7q8t Transmit Queues 1p3q1t Transmit Queues 1p2q1t Transmit Queues Default Values With PFC QoS Disabled PFC QoS Configuration Guidelines and Restrictions General Guidelines PFC3 Guidelines PFC2 Guidelines Class Map Command Restrictions Policy Map Command Restrictions Policy Map Class Command Restrictions Supported Granularity for CIR and PIR Rate Values Supported Granularity for CIR and PIR Token Bucket Sizes IP Precedence and DSCP Values Configuring PFC QoS Enabling PFC QoS Globally Enabling Ignore Port Trust Configuring DSCP Transparency Enabling Queueing-Only Mode Enabling Microflow Policing of Bridged Traffic Enabling VLAN-Based PFC QoS on Layer 2 LAN Ports Enabling Egress ACL Support for Remarked DSCP Creating Named Aggregate Policers Page Page Configuring a PFC QoS Policy PFC QoS Policy Configuration Overview Configuring MAC ACLs Configuring Protocol-Independent MAC ACL Filtering Enabling VLAN-Based MAC QoS Filtering Configuring MAC ACLs Configuring ARP ACLs for QoS Filtering Configuring a Class Map Creating a Class Map Class Map Filtering Guidelines and Restrictions Configuring Filtering in a Class Map Verifying Class Map Configuration Configuring a Policy Map Creating a Policy Map Policy Map Class Configuration Guidelines and Restrictions Creating a Policy Map Class and Configuring Filtering Configuring Policy Map Class Actions Page Page Page Page Verifying Policy Map Configuration Attaching a Policy Map to an Interface Page Configuring Egress DSCP Mutation on a PFC3 Configuring Named DSCP Mutation Maps Attaching an Egress DSCP Mutation Map to an Interface Configuring Ingress CoS Mutation on IEEE 802.1Q Tunnel Ports Ingress CoS Mutation Configuration Guidelines and Restrictions Configuring Ingress CoS Mutation Maps Applying Ingress CoS Mutation Maps to IEEE 802.1Q Tunnel Ports Configuring DSCP Value Maps Mapping Received CoS Values to Internal DSCP Values Mapping Received IP Precedence Values to Internal DSCP Values Configuring DSCP Markdown Values Page Mapping Internal DSCP Values to Egress CoS Values Configuring the Trust State of Ethernet LAN and OSM Ports Configuring the Ingress LAN Port CoS Value Configuring Standard-Queue Drop Threshold Percentages Configuring a Tail-Drop Receive Queue Configuring a WRED-Drop Transmit Queue Configuring a WRED-Drop and Tail-Drop Receive Queue Configuring a WRED-Drop and Tail-Drop Transmit Queue Configuring 1q4t/2q2t Tail-Drop Threshold Percentages Page Mapping QoS Labels to Queues and Drop Thresholds Queue and Drop Threshold Mapping Guidelines and Restrictions Configuring DSCP-Based Queue Mapping Enabling DSCP-Based Queue Mapping Configuring Ingress DSCP-Based Queue Mapping Page Note The receive queue mapping is shown in the second queue thresh dscp-map displayed by the show queueing interface command. This example shows how to verify the configuration: Mapping DSCP Values to Standard Transmit-Queue Thresholds Mapping DSCP Values to the Transmit Strict-Priority Queue Mapping CoS Values to Standard Receive-Queue Thresholds Mapping CoS Values to Standard Transmit-Queue Thresholds Mapping CoS Values to Strict-Priority Queues Mapping CoS Values to Tail-Drop Thresholds on 1q4t/2q2t LAN Ports Allocating Bandwidth Between Standard Transmit Queues Page Setting the Receive-Queue Size Ratio Configuring the Transmit-Queue Size Ratio Common QoS Scenarios Sample Network Design Overview Classifying Traffic from PCs and IP Phones in the Access Layer Page Page Accepting the Traffic Priority Value on Interswitch Links Prioritizing Traffic on Interswitch Links Page Page Using Policers to Limit the Amount of Traffic from a PC Page PFC QoS Glossary