Concept Guide

48 Security................................................................................................................................................... 753
AAA Accounting.............................................................................................................................................................753
Conguration Task List for AAA Accounting........................................................................................................ 753
AAA Authentication.......................................................................................................................................................755
Conguration Task List for AAA Authentication.................................................................................................. 756
Obscuring Passwords and Keys...................................................................................................................................759
AAA Authorization......................................................................................................................................................... 759
Privilege Levels Overview.......................................................................................................................................759
Conguration Task List for Privilege Levels..........................................................................................................760
RADIUS........................................................................................................................................................................... 764
RADIUS Authentication...........................................................................................................................................764
Conguration Task List for RADIUS.......................................................................................................................765
Support for Change of Authorization and Disconnect Messages packets...................................................... 769
TACACS+........................................................................................................................................................................780
Conguration Task List for TACACS+................................................................................................................... 780
TACACS+ Remote Authentication.........................................................................................................................782
Command Authorization......................................................................................................................................... 783
Protection from TCP Tiny and Overlapping Fragment Attacks............................................................................... 783
Enabling SCP and SSH..................................................................................................................................................783
Using SCP with SSH to Copy a Software Image.................................................................................................784
Removing the RSA Host Keys and Zeroizing Storage ........................................................................................785
Conguring When to Re-generate an SSH Key ..................................................................................................785
Conguring the SSH Server Key Exchange Algorithm....................................................................................... 786
Conguring the HMAC Algorithm for the SSH Server....................................................................................... 786
Conguring the SSH Server Cipher List............................................................................................................... 787
Conguring DNS in the SSH Server......................................................................................................................787
Secure Shell Authentication....................................................................................................................................788
Troubleshooting SSH...............................................................................................................................................790
Telnet...............................................................................................................................................................................790
VTY Line and Access-Class Conguration.................................................................................................................. 791
VTY Line Local Authentication and Authorization................................................................................................ 791
VTY Line Remote Authentication and Authorization...........................................................................................792
VTY MAC-SA Filter Support...................................................................................................................................792
Role-Based Access Control.......................................................................................................................................... 792
Overview of RBAC...................................................................................................................................................793
User Roles.................................................................................................................................................................795
AAA Authentication and Authorization for Roles.................................................................................................798
Role Accounting........................................................................................................................................................801
Display Information About User Roles...................................................................................................................802
Two Factor Authentication (2FA)................................................................................................................................ 803
Handling Access-Challenge Message................................................................................................................... 803
Conguring Challenge Response Authentication for SSHv2............................................................................. 803
SMS-OTP Mechanism............................................................................................................................................804
Conguring the System to Drop Certain ICMP Reply Messages............................................................................804
Dell EMC Networking OS Security Hardening...........................................................................................................806
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