Exam CCSP topic 1 question 305 discussion

IPSec (Internet Protocol Security) operates at the Network Layer (Layer 3) of the OSI model and provides end-to-end encryption for all communications between networked devices. It is commonly used for VPNs, secure remote access, and site-to-site encryption. Why Not the Others? B. VPN: VPN (Virtual Private Network) is a broader concept that can use different protocols (including IPSec, SSL, or TLS) for secure tunneling, but it is not a protocol itself. C. SSL: Secure Sockets Layer (SSL) operates at Layer 4-7 and is mostly obsolete, replaced by TLS for encrypting web traffic. D. TLS: Transport Layer Security (TLS) works at Layer 4 (Transport Layer) and encrypts application-layer communications like HTTPS but does not encrypt all network traffic like IPSec does.

VPN (Virtual Private Network) is not the correct answer to the previous question because it is not a protocol.

A: IPSec

IPSec and TLS are protocols. IPSec is network layer as the question asks. TLS is layer 4-7 so higher.

B. VPN

The answer reasoning specifically states why VPN is NOT the right answer: "Although a VPN allows a secure channel for communications into a private network from an outside location, it's not a protocol." The question is asking which "protocol" would be used, not technology. Therefore the only right answer is IPsec

Yeah this is not totally write. VPN would have been closer. In transport mode, IPsec never encrypts the IP header data (information such as the source and destination address), but in tunnel mode the IP header and payload are encrypted