Glossary

AAA (authentication, authorization, accounting)—

Often pronounced “triple a.”

ACS (Access Control Server)—

The Cisco Secure ACS is an integrated RADIUS and TACACS+ server for authentication, authorization, and accounting.

CCO (Cisco Connection Online)—

The Cisco Systems home page on the Internet. Located at www.cisco.com.

CLI (command-line interface)—

The UNIX-style command interface that is used to configure Cisco internetworking devices.

IDS (Intrusion Detection System)—

Scans the network in real time to intercept attempted breaches of security.

ISP (Internet service provider)—

A service provider that provides a connection to the public Internet.

IPSec (Internet Protocol Security)—

A standards-based method of providing privacy, integrity, and authenticity to information transferred across IP networks.

NAS (network access server)—

The connection point to the network for remote services, such as dial-in users over PPP.

NOS (network operating system)—

The operating system of the network. This provides services to users such as file and print sharing. Common NOSs include Microsoft Windows NT and Novell NetWare.

PIX (Private Internet Exchange)—

The Cisco range of leading hardware-based firewalls.

RADIUS (Remote Access Dial-In User Service)—

A protocol used to authenticate users on a network.

TACACS+ (Terminal Access Controller Access Control System Plus)—

A protocol used to authenticate users on a network. Also provides authorization and accounting facilities.

VPN (Virtual Private Network)—

A secure connection over an unsecured medium. The connection is secured by the use of tunneling protocols and encryption.