Concept Guide

Protocol Overview......................................................................................................................................................... 884
Conguring Rapid Spanning Tree................................................................................................................................ 884
Related Conguration Tasks...................................................................................................................................884
Important Points to Remember................................................................................................................................... 884
RSTP and VLT..........................................................................................................................................................885
Conguring Interfaces for Layer 2 Mode....................................................................................................................885
Enabling Rapid Spanning Tree Protocol Globally........................................................................................................886
Adding and Removing Interfaces.................................................................................................................................888
Modifying Global Parameters....................................................................................................................................... 888
Enabling SNMP Traps for Root Elections and Topology Changes.....................................................................889
Modifying Interface Parameters.................................................................................................................................. 890
Inuencing RSTP Root Selection.................................................................................................................................890
Conguring an EdgePort............................................................................................................................................... 891
Conguring Fast Hellos for Link State Detection....................................................................................................... 891
50 Security...................................................................................................................................................893
Role-Based Access Control..........................................................................................................................................893
Overview of RBAC.................................................................................................................................................. 893
User Roles................................................................................................................................................................ 896
AAA Authentication and Authorization for Roles................................................................................................ 899
Role Accounting.......................................................................................................................................................902
Display Information About User Roles...................................................................................................................903
AAA Accounting.............................................................................................................................................................904
Conguration Task List for AAA Accounting........................................................................................................904
AAA Authentication.......................................................................................................................................................906
Conguration Task List for AAA Authentication.................................................................................................. 906
AAA Authorization..........................................................................................................................................................910
Privilege Levels Overview........................................................................................................................................910
Conguration Task List for Privilege Levels...........................................................................................................910
RADIUS............................................................................................................................................................................915
RADIUS Authentication and Authorization........................................................................................................... 915
Conguration Task List for RADIUS....................................................................................................................... 916
Support for Change of Authorization and Disconnect Messages packets...................................................... 920
TACACS+........................................................................................................................................................................929
Conguration Task List for TACACS+...................................................................................................................929
TACACS+ Remote Authentication and Authorization..........................................................................................931
Command Authorization.........................................................................................................................................932
Protection from TCP Tiny and Overlapping Fragment Attacks............................................................................... 932
Enabling SCP and SSH................................................................................................................................................. 932
Using SCP with SSH to Copy a Software Image................................................................................................ 933
Removing the RSA Host Keys and Zeroizing Storage ....................................................................................... 934
Conguring When to Re-generate an SSH Key ..................................................................................................934
Conguring the SSH Server Cipher List...............................................................................................................935
Conguring DNS in the SSH Server..................................................................................................................... 935
Conguring the HMAC Algorithm for the SSH Server.......................................................................................936
Conguring the HMAC Algorithm for the SSH Client.........................................................................................936
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Contents