Concept Guide

Recover from a Card Problem State on a Stack.................................................................................................1015
55 Storm Control......................................................................................................................................... 1017
Congure Storm Control..............................................................................................................................................1017
Conguring Storm Control from INTERFACE Mode.......................................................................................... 1017
Conguring Storm Control from CONFIGURATION Mode............................................................................... 1018
56 Spanning Tree Protocol (STP)................................................................................................................ 1019
Protocol Overview........................................................................................................................................................ 1019
Congure Spanning Tree.............................................................................................................................................1020
Related Conguration Tasks................................................................................................................................. 1020
Important Points to Remember..................................................................................................................................1020
Conguring Interfaces for Layer 2 Mode...................................................................................................................1021
Enabling Spanning Tree Protocol Globally................................................................................................................. 1022
Adding an Interface to the Spanning Tree Group.....................................................................................................1024
Modifying Global Parameters......................................................................................................................................1024
Modifying Interface STP Parameters........................................................................................................................ 1025
Enabling PortFast.........................................................................................................................................................1025
Prevent Network Disruptions with BPDU Guard............................................................................................... 1026
Selecting STP Root......................................................................................................................................................1028
STP Root Guard........................................................................................................................................................... 1028
Root Guard Scenario..............................................................................................................................................1028
Conguring Root Guard........................................................................................................................................ 1029
Enabling SNMP Traps for Root Elections and Topology Changes......................................................................... 1030
Conguring Spanning Trees as Hitless...................................................................................................................... 1030
STP Loop Guard...........................................................................................................................................................1030
Conguring Loop Guard........................................................................................................................................ 1032
Displaying STP Guard Conguration..........................................................................................................................1032
57 SupportAssist.........................................................................................................................................1034
Conguring SupportAssist Using a Conguration Wizard...................................................................................... 1035
Conguring SupportAssist Manually..........................................................................................................................1035
Conguring SupportAssist Activity............................................................................................................................ 1037
Conguring SupportAssist Company.........................................................................................................................1038
Conguring SupportAssist Person.............................................................................................................................1039
Conguring SupportAssist Server............................................................................................................................. 1039
Viewing SupportAssist Conguration........................................................................................................................1040
58 System Time and Date........................................................................................................................... 1042
Network Time Protocol............................................................................................................................................... 1042
Protocol Overview................................................................................................................................................. 1043
Congure the Network Time Protocol................................................................................................................ 1043
Enabling NTP..........................................................................................................................................................1044
Conguring NTP Broadcasts................................................................................................................................1044
Disabling NTP on an Interface..............................................................................................................................1045
Conguring a Source IP Address for NTP Packets........................................................................................... 1045
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