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Protocol Overview......................................................................................................................................................... 767
Conguring Rapid Spanning Tree.................................................................................................................................767
Related Conguration Tasks................................................................................................................................... 767
Important Points to Remember....................................................................................................................................767
RSTP and VLT..........................................................................................................................................................768
Conguring Interfaces for Layer 2 Mode....................................................................................................................768
Enabling Rapid Spanning Tree Protocol Globally........................................................................................................769
Adding and Removing Interfaces..................................................................................................................................771
Modifying Global Parameters........................................................................................................................................ 771
Enabling SNMP Traps for Root Elections and Topology Changes..................................................................... 773
Modifying Interface Parameters...................................................................................................................................773
Enabling SNMP Traps for Root Elections and Topology Changes........................................................................... 773
Inuencing RSTP Root Selection................................................................................................................................. 774
Conguring an EdgePort...............................................................................................................................................774
Conguring Fast Hellos for Link State Detection.......................................................................................................775
45 Software-Dened Networking (SDN)...................................................................................................... 776
46 Security................................................................................................................................................... 777
AAA Accounting............................................................................................................................................................. 777
Conguration Task List for AAA Accounting.........................................................................................................777
AAA Authentication....................................................................................................................................................... 779
Conguration Task List for AAA Authentication.................................................................................................. 780
Obscuring Passwords and Keys................................................................................................................................... 783
AAA Authorization......................................................................................................................................................... 783
Privilege Levels Overview....................................................................................................................................... 783
Conguration Task List for Privilege Levels.......................................................................................................... 784
RADIUS........................................................................................................................................................................... 788
RADIUS Authentication...........................................................................................................................................788
Conguration Task List for RADIUS.......................................................................................................................789
Support for Change of Authorization and Disconnect Messages packets.......................................................792
TACACS+........................................................................................................................................................................ 801
Conguration Task List for TACACS+....................................................................................................................801
TACACS+ Remote Authentication.........................................................................................................................803
Command Authorization.........................................................................................................................................804
Protection from TCP Tiny and Overlapping Fragment Attacks...............................................................................805
Enabling SCP and SSH................................................................................................................................................. 805
Using SCP with SSH to Copy a Software Image................................................................................................ 806
Removing the RSA Host Keys and Zeroizing Storage ........................................................................................807
Conguring When to Re-generate an SSH Key ..................................................................................................807
Conguring the SSH Server Key Exchange Algorithm....................................................................................... 807
Conguring the HMAC Algorithm for the SSH Server.......................................................................................808
Conguring the SSH Server Cipher List...............................................................................................................808
Secure Shell Authentication................................................................................................................................... 809
Troubleshooting SSH................................................................................................................................................ 811
Telnet................................................................................................................................................................................812
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