Concept Guide

49 Software-Dened Networking (SDN)...................................................................................................... 846
50 Security...................................................................................................................................................847
AAA Accounting.............................................................................................................................................................847
Conguration Task List for AAA Accounting........................................................................................................ 847
AAA Authentication.......................................................................................................................................................849
Conguration Task List for AAA Authentication.................................................................................................. 850
Obscuring Passwords and Keys...................................................................................................................................853
AAA Authorization......................................................................................................................................................... 853
Privilege Levels Overview.......................................................................................................................................853
Conguration Task List for Privilege Levels..........................................................................................................854
RADIUS...........................................................................................................................................................................858
RADIUS Authentication...........................................................................................................................................858
Conguration Task List for RADIUS...................................................................................................................... 859
Support for Change of Authorization and Disconnect Messages packets...................................................... 863
TACACS+........................................................................................................................................................................ 874
Conguration Task List for TACACS+....................................................................................................................874
TACACS+ Remote Authentication.........................................................................................................................876
Command Authorization..........................................................................................................................................877
Protection from TCP Tiny and Overlapping Fragment Attacks................................................................................877
Enabling SCP and SSH..................................................................................................................................................877
Using SCP with SSH to Copy a Software Image.................................................................................................878
Removing the RSA Host Keys and Zeroizing Storage ........................................................................................879
Conguring When to Re-generate an SSH Key ..................................................................................................879
Conguring the SSH Server Key Exchange Algorithm.......................................................................................880
Conguring the HMAC Algorithm for the SSH Server.......................................................................................880
Conguring the HMAC Algorithm for the SSH Client......................................................................................... 881
Conguring the SSH Server Cipher List................................................................................................................881
Conguring the SSH Client Cipher List................................................................................................................ 882
Conguring DNS in the SSH Server......................................................................................................................882
Secure Shell Authentication................................................................................................................................... 883
Troubleshooting SSH...............................................................................................................................................885
Telnet...............................................................................................................................................................................886
VTY Line and Access-Class Conguration................................................................................................................. 886
VTY Line Local Authentication and Authorization............................................................................................... 886
VTY Line Remote Authentication and Authorization...........................................................................................887
VTY MAC-SA Filter Support...................................................................................................................................887
Role-Based Access Control..........................................................................................................................................888
Overview of RBAC.................................................................................................................................................. 888
User Roles................................................................................................................................................................ 890
AAA Authentication and Authorization for Roles.................................................................................................894
Role Accounting.......................................................................................................................................................896
Display Information About User Roles................................................................................................................... 897
Two Factor Authentication (2FA)................................................................................................................................ 898
Handling Access-Challenge Message................................................................................................................... 899
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