AAA: AUTHENTICATION

• AAA Refers to a variety of common security features.
• AAA: Authentication, Authorization & Accounting
• The strongest authentication method to protect CLI are:
• TACACS+ 
• RADIUS server 
• The Cisco Secure Access Control Server (ACS) 
• It is a cisco systems software product
• It can be installed on unix, linux & several windows platforms.
• It holds a set of usernames & passwords used for authentication
• Routers & Switches send Usernames & passwords from users are sent to server in encrypted manner.
• 
  

• 	RADIUS	TACACS+
  Scope of Encryption: Packet payload or just the password	Password only	Entire Payload
  Layer 4 Protocol	UDP	TCP
  Well-known Port/IOS default port used for authentication	1812/1645	49/49
  Standard or CISCO Proprietary	RFC 2865	Proprietary