Cisco Certified Network Associate (CCNA) Practice Exam

Which tunneling protocol does not provide encryption but relies on PPP for packet encryption?

1. Layer 2 Tunneling Protocol

2. Layer 2 Forwarding

3. Secure Socket Layer

4. Point-to-Point Tunneling Protocol

The correct answer is: Layer 2 Forwarding

The correct answer is based on understanding the characteristics of tunneling protocols and their capabilities regarding encryption. Point-to-Point Tunneling Protocol (PPTP) is a tunneling protocol that facilitates the secure transfer of data across a public network through encapsulation. While PPTP itself does not provide encryption, it utilizes the existing Point-to-Point Protocol (PPP) for encryption. PPP allows the establishment of a direct connection between two nodes and provides a means for the secure transmission of data through compression and encryption techniques. PPTP is designed to work over the Internet by encapsulating PPP frames inside IP packets, which can then traverse through various networking infrastructures. While PPTP has come under scrutiny for security vulnerabilities over time, its reliance on PPP for encryption distinguishes it from other tunneling protocols that may provide their own encryption mechanisms directly. The other options listed involve different functionalities or encryption capabilities and do not align with the characteristics highlighted in the question. For instance, Layer 2 Tunneling Protocol (L2TP) is meant for tunneling data but typically is paired with other encryption protocols like IPsec to provide security. Secure Socket Layer (SSL) is a security protocol that provides encrypted connections but is not specific to tunneling as a primary function.