White Papers

VLT Non-fail over Scenario.....................................................................................................................................694
VLT Fail-over Scenario............................................................................................................................................695
RPM over VLT Scenarios....................................................................................................................................... 695
39 Per-VLAN Spanning Tree Plus (PVST+)................................................................................................... 697
Protocol Overview......................................................................................................................................................... 697
Implementation Information......................................................................................................................................... 698
Congure Per-VLAN Spanning Tree Plus................................................................................................................... 698
Related Conguration Tasks...................................................................................................................................698
Enabling PVST+............................................................................................................................................................. 698
Disabling PVST+.............................................................................................................................................................699
Inuencing PVST+ Root Selection.............................................................................................................................. 699
Modifying Global PVST+ Parameters...........................................................................................................................701
Modifying Interface PVST+ Parameters..................................................................................................................... 702
Conguring an EdgePort.............................................................................................................................................. 703
PVST+ in Multi-Vendor Networks................................................................................................................................703
Enabling PVST+ Extend System ID............................................................................................................................. 703
PVST+ Sample Congurations.....................................................................................................................................704
40 Quality of Service (QoS)..........................................................................................................................707
Implementation Information..........................................................................................................................................709
Port-Based QoS Congurations.................................................................................................................................. 709
Setting dot1p Priorities for Incoming Trac......................................................................................................... 709
Honoring dot1p Priorities on Ingress Trac...........................................................................................................710
Conguring Port-Based Rate Policing.................................................................................................................... 711
Conguring Port-Based Rate Shaping....................................................................................................................711
Policy-Based QoS Congurations.................................................................................................................................712
Classify Trac...........................................................................................................................................................712
Dot1p to Queue Mapping Requirement................................................................................................................. 716
Create a QoS Policy................................................................................................................................................. 716
DSCP Color Maps.................................................................................................................................................... 719
Create Policy Maps...................................................................................................................................................721
Enabling QoS Rate Adjustment....................................................................................................................................725
Enabling Strict-Priority Queueing................................................................................................................................ 726
Queue Classication Requirements for PFC Functionality....................................................................................... 726
Support for marking dot1p value in L3 Input Qos Policy...........................................................................................726
Weighted Random Early Detection.............................................................................................................................. 727
Enabling and Disabling WRED Globally..................................................................................................................728
Creating WRED Proles.......................................................................................................................................... 728
Applying a WRED Prole to Trac........................................................................................................................ 729
Displaying Default and Congured WRED Proles.............................................................................................. 729
Displaying WRED Drop Statistics...........................................................................................................................729
Displaying egress–queue Statistics....................................................................................................................... 729
Pre-Calculating Available QoS CAM Space................................................................................................................ 730
Specifying Policy-Based Rate Shaping in Packets Per Second................................................................................ 731
Conguring Policy-Based Rate Shaping...................................................................................................................... 731
Contents
23