Users Guide

Add Units to an Existing Stack...............................................................................................................................873
Split a Stack..............................................................................................................................................................875
Stacking Configuration Tasks...................................................................................................................................... 876
Assigning Unit Numbers to Units in an Stack...................................................................................................... 876
Creating a Virtual Stack Unit on a Stack.............................................................................................................. 876
Displaying Information about a Stack....................................................................................................................877
Influencing Management Unit Selection on a Stack........................................................................................... 879
Managing Redundancy on a Stack........................................................................................................................879
Resetting a Unit on a Stack....................................................................................................................................879
Verify a Stack Configuration........................................................................................................................................880
Displaying the Status of Stacking Ports...............................................................................................................880
Remove Units or Front End Ports from a Stack........................................................................................................ 881
Removing a Unit from a Stack...............................................................................................................................882
Removing Front End Port Stacking...................................................................................................................... 882
Troubleshoot a Stack....................................................................................................................................................883
Recover from Stack Link Flaps..............................................................................................................................883
Recover from a Card Problem State on a Stack.................................................................................................883
Recover from a Card Mismatch State on a Stack..............................................................................................884
52 Storm Control..........................................................................................................................................886
Configure Storm Control..............................................................................................................................................886
Configuring Storm Control from INTERFACE Mode..........................................................................................886
Configuring Storm Control from CONFIGURATION Mode............................................................................... 887
53 Spanning Tree Protocol (STP)................................................................................................................ 888
Protocol Overview.........................................................................................................................................................888
Configure Spanning Tree..............................................................................................................................................889
Related Configuration Tasks..................................................................................................................................889
Important Points to Remember...................................................................................................................................889
Configuring Interfaces for Layer 2 Mode...................................................................................................................890
Enabling Spanning Tree Protocol Globally...................................................................................................................891
Adding an Interface to the Spanning Tree Group..................................................................................................... 893
Modifying Global Parameters.......................................................................................................................................893
Modifying Interface STP Parameters......................................................................................................................... 894
Enabling PortFast.......................................................................................................................................................... 894
Prevent Network Disruptions with BPDU Guard................................................................................................ 895
Selecting STP Root....................................................................................................................................................... 897
STP Root Guard.............................................................................................................................................................897
Root Guard Scenario...............................................................................................................................................897
Configuring Root Guard..........................................................................................................................................898
Enabling SNMP Traps for Root Elections and Topology Changes......................................................................... 899
Configuring Spanning Trees as Hitless....................................................................................................................... 899
STP Loop Guard............................................................................................................................................................ 899
Configuring Loop Guard.......................................................................................................................................... 901
Displaying STP Guard Configuration............................................................................................................................901
28
Contents