71Authentication, Authorization, andAccounting fundamentalsAAA provides a modular way of performing the following services:• Authentication• Authorization• AccountingAuthenticationAuthentication determines how a user is identified prior to being allowedaccess to the network and network services. You configure AAAauthentication by defining a named list of authentication methods, andthen applying that list to various interfaces. The method list defines thetypes of authentication to be performed and the sequence in which theyare performed; it must be applied to a specific interface before any of thedefined authentication methods can be performed. The only exception isthe default method list. The default method list is automatically applied to allinterfaces if no other method list is defined. A defined method list overridesthe default method list.All authentication methods, except for local, line password, and enableauthentication, must be defined through AAA.SR4134 supports the following authentication methods:PAP authenticationPassword Authentication Protocol (PAP) is a simple authentication protocolused to authenticate a user to a remote access server or Internet serviceprovider (ISP). Almost all network operating system remote servers supportPAP. PAP transmits unencrypted ASCII passwords over the network andis therefore considered insecure.)Nortel Secure Router 4134Security — Configuration and ManagementNN47263-600 01.02 Standard10.0 3 August 2007Copyright © 2007, Nortel Networks.
