Cisco Certified Internetwork Expert (CCIE) Practice Test

Which EAP protocol provides support for Fast Reauthentication?

1. EAP-FAST

2. EAP-TLS

3. EAP-MD5

4. EAP-SRP

The correct answer is: EAP-FAST

EAP-FAST, or Extensible Authentication Protocol - Flexible Authentication via Secure Tunneling, is specifically designed to provide support for fast reauthentication. This feature allows for quick re-establishment of the secure connection between the client and the authentication server, significantly improving the speed of the authentication process, particularly in environments where clients frequently disconnect and reconnect. Fast reauthentication is achieved through the use of a tunnel that maintains a secure session after the initial authentication. This means that once a client has been authenticated, subsequent reauthentications can take place without needing to go through the full process again, thus speeding up the overall procedure and reducing latency. The other options, while being authentication protocols, do not inherently support fast reauthentication in the same manner. EAP-TLS, for instance, relies on certificate-based authentication that requires a more extensive setup and validation process each time, which does not lend itself to quick recoveries. EAP-MD5, on the other hand, is a simple challenge-response mechanism without the capabilities for secure session management that facilitate fast reauthentication. Lastly, EAP-SRP is focused on password-based authentication through secure remote passwords but lacks the mechanisms for speedily reauthenticating in an established session. Therefore, EAP