Concept Guide

High Availability on Stacks....................................................................................................................................... 911
Management Access on Stacks..............................................................................................................................911
Important Points to Remember.................................................................................................................................... 912
Stacking Installation Tasks.............................................................................................................................................912
Create a Stack.......................................................................................................................................................... 912
Add Units to an Existing Stack............................................................................................................................... 916
Split a Stack.............................................................................................................................................................. 919
Stacking Conguration Tasks........................................................................................................................................919
Assigning Unit Numbers to Units in an Stack....................................................................................................... 919
Creating a Virtual Stack Unit on a Stack.............................................................................................................. 920
Displaying Information about a Stack....................................................................................................................920
Inuencing Management Unit Selection on a Stack........................................................................................... 922
Managing Redundancy on a Stack........................................................................................................................922
Resetting a Unit on a Stack....................................................................................................................................923
Verify a Stack Conguration.........................................................................................................................................923
Displaying the Status of Stacking Ports................................................................................................................923
Remove Units or Front End Ports from a Stack........................................................................................................925
Removing a Unit from a Stack............................................................................................................................... 925
Removing Front End Port Stacking.......................................................................................................................926
Troubleshoot a Stack.....................................................................................................................................................926
Recover from Stack Link Flaps.............................................................................................................................. 926
Recover from a Card Problem State on a Stack..................................................................................................927
Recover from a Card Mismatch State on a Stack............................................................................................... 927
52 Storm Control..........................................................................................................................................929
Congure Storm Control...............................................................................................................................................929
Conguring Storm Control from INTERFACE Mode...........................................................................................929
Conguring Storm Control from CONFIGURATION Mode................................................................................930
53 Spanning Tree Protocol (STP)..................................................................................................................931
Protocol Overview..........................................................................................................................................................931
Congure Spanning Tree...............................................................................................................................................932
Related Conguration Tasks...................................................................................................................................932
Important Points to Remember................................................................................................................................... 932
Conguring Interfaces for Layer 2 Mode....................................................................................................................933
Enabling Spanning Tree Protocol Globally...................................................................................................................934
Adding an Interface to the Spanning Tree Group...................................................................................................... 936
Modifying Global Parameters....................................................................................................................................... 936
Modifying Interface STP Parameters.......................................................................................................................... 937
Enabling PortFast...........................................................................................................................................................937
Prevent Network Disruptions with BPDU Guard.................................................................................................938
Selecting STP Root....................................................................................................................................................... 940
STP Root Guard.............................................................................................................................................................940
Root Guard Scenario...............................................................................................................................................940
Conguring Root Guard...........................................................................................................................................941
Enabling SNMP Traps for Root Elections and Topology Changes...........................................................................942
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