Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

Network Access Security 133
including Microsoft Windows 2003 Internet Authentication Services (IASes),
Microsoft Windows 2008 Network Policy Server (NPS), and Linux systems using
Kerberos or through non-OS implementations such as RSA Enterprise Single
Sign-On (ESSO) solutions.
Authentication Services
Authentication services refer to the directory services accessed before the users
are authenticated or services used to authenticate.
REMOTE ACCESS SERVICES
Remote access policies go beyond just authenticating the user. These policies
define how the users can connect to the network. You may also grant or deny the
permission to dial-in, based on the credentials presented by the remote users.
A remote access policy defines the conditions, remote access permissions, and
creates a profile for every remote connection made to the corporate network.
Through remote access policies you can define the following:
■ Grant or deny dial-in based on connection parameters such as type and
time of the day
■ Authentication protocols (Password Authentication Protocol (PAP), CHAP,
EAP, MS-CHAP)
■ Validation of the caller id
■ Call back
■ Apply connection restrictions upon successful authorization
■ Create remote user/connection profile
■ Assign a static IP or dynamic IP from the address pool defined for remote
users
■ Assign the user to a group to apply group policies
■ Configure remote access permission parameters
■ Define encryption parameters (for a remote access VPN client)
■ Control the duration of the session including maximum time allowed and
the idle time before the connection is reset
Remote access policies can be configured in Microsoft Windows 2003 through
IAS, in Windows 2008 through NPS and in Linux variants through Free Remote
Authentication Dial-In User Service (RADIUS).
REMOTE AUTHENTICATION DIAL-IN USER SERVICE AND BIOMETRICS
When users dial into a network, RADIUS is used to authenticate usernames and
passwords. A RADIUS server can either work alone or in a distributed environment,
known as distributed RADIUS, where RADIUS servers are configured in a
hierarchical structure. RADIUS supports a number of protocols including the
following:
■
■
■
Point-to-Point Protocol (PPP)
Password Authentication Protocol (PAP)
Challenge Handshake Authentication Protocol (CHAP.)