White Papers

Table Of Contents
Protocol Overview..........................................................................................................................................................689
Implementation Information......................................................................................................................................... 690
Configure Per-VLAN Spanning Tree Plus..................................................................................................................691
Enabling PVST+............................................................................................................................................................... 691
Disabling PVST+.............................................................................................................................................................. 691
Influencing PVST+ Root Selection............................................................................................................................. 692
Modifying Global PVST+ Parameters........................................................................................................................ 693
Modifying Interface PVST+ Parameters................................................................................................................... 693
Configuring an EdgePort...............................................................................................................................................694
PVST+ in Multi-Vendor Networks.............................................................................................................................. 695
Enabling PVST+ Extend System ID............................................................................................................................ 695
PVST+ Sample Configurations.................................................................................................................................... 696
Chapter 42: Quality of Service (QoS)........................................................................................ 698
Implementation Information......................................................................................................................................... 700
Port-Based QoS Configurations..................................................................................................................................700
Setting dot1p Priorities for Incoming Traffic...................................................................................................... 700
Honoring dot1p Priorities on Ingress Traffic........................................................................................................701
Configuring Port-Based Rate Policing.................................................................................................................. 701
Configuring Port-Based Rate Shaping..................................................................................................................701
Policy-Based QoS Configurations............................................................................................................................... 702
Classify Traffic...........................................................................................................................................................703
Dot1p to Queue Mapping Requirement................................................................................................................705
Create a QoS Policy................................................................................................................................................. 706
DSCP Color Maps..................................................................................................................................................... 708
Create Policy Maps................................................................................................................................................... 710
Enabling QoS Rate Adjustment.................................................................................................................................... 713
Enabling Strict-Priority Queueing................................................................................................................................ 713
Queue Classification Requirements for PFC Functionality.................................................................................... 714
Support for marking dot1p value in L3 Input Qos Policy........................................................................................ 714
Weighted Random Early Detection..............................................................................................................................715
Enabling and Disabling WRED Globally................................................................................................................. 715
Creating WRED Profiles........................................................................................................................................... 716
Applying a WRED Profile to Traffic....................................................................................................................... 716
Displaying Default and Configured WRED Profiles............................................................................................ 716
Displaying WRED Drop Statistics........................................................................................................................... 716
Displaying egressqueue Statistics....................................................................................................................... 716
Pre-Calculating Available QoS CAM Space............................................................................................................... 717
Specifying Policy-Based Rate Shaping in Packets Per Second............................................................................718
Configuring Policy-Based Rate Shaping.....................................................................................................................718
Configuring Weights and ECN for WRED .................................................................................................................719
Configuring WRED and ECN Attributes.................................................................................................................... 720
Guidelines for Configuring ECN for Classifying and Color-Marking Packets....................................................721
Sample configuration to mark non-ecn packets as yellow with Multiple traffic class...........................721
Classifying Incoming Packets Using ECN and Color-Marking........................................................................722
Sample configuration to mark non-ecn packets as yellow with single traffic class.............................. 723
Applying Layer 2 Match Criteria on a Layer 3 Interface........................................................................................724
Managing Hardware Buffer Statistics..................................................................................................................725
Enabling Buffer Statistics Tracking ........................................................................................................................... 725
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