TACACS+
TACACS+ is the standard for managing network infrastructure logins. Cisco, Juniper, and Aruba devices all support it. Any NOC that uses TACACS+ via Cisco ISE or Tac_Plus needs engineers who understand the AAA separation model.
What It Defines
TACACS+ (Terminal Access Controller Access-Control System Plus) provides AAA for network device administration: router/switch CLI login, command authorization, and audit logging. Separates authentication, authorization, and accounting into independent exchanges. Encrypts the entire packet body (unlike RADIUS which only encrypts the password). RFC 8907 is the first formal IETF standardization after decades as a Cisco de facto standard.
Canonical (Normative)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
RADIUS is the AAA protocol behind every enterprise Wi-Fi login, VPN authentication, and 802.1X deployment. FreeRADIUS, Cisco ISE, and Aruba ClearPass all implement it. Essential for understanding corporate network access and SSO integration.
Diameter is the AAA backbone of LTE and IMS networks. If you build carrier infrastructure or work on 4G/5G billing and policy enforcement, you'll encounter Diameter on the S6a, Rx, Gx, and Gy interfaces.