Terminal Access Controller Access Control System (TACACS+)

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Terminal Access Controller Access Control System (TACACS+) is a AAA protocol developed by Cisco that is often used to authenticate to administrator accounts for network appliance management.

• similar to RADIUS, but more flexible and reliable
• supported on
  • Cisco
  • third-party
  • open-source RADIUS servers
• often used in authenticating administrative access to routers and switches
• uses TCP port 49
  • reliable delivery of TCP makes it easier to detect when a server goes down
• AAA functions are discrete (separate)
  • many device management tasks require
    • reauthentication
    • per-command authorizations and privileges
• supports this workflow better than RADIUS