Internet Protocol Security IPSec is actually a suite of protocols. Each protocol within the suite provides different functionality. Collective IPSec does everything except.

IPSec is a Layer 3 (Network Layer) protocol suite defined in RFC 4301 that secures IP traffic by embedding security directly into IP packets. It does not operate at Layer 2 (the Data Link Layer), which is the domain of protocols like Ethernet, Wi-Fi, and PPP. Protocols such as MACsec operate at Layer 2; IPSec's design scope explicitly begins at the IP layer.

IPSec in tunnel mode encapsulates and protects both the original payload and the original IP headers, so protecting headers is within its functional scope.

IPSec uses ESP (Encapsulating Security Payload) to provide confidentiality through encryption of the packet payload.

IPSec uses AH (Authentication Header) and ESP to provide data origin authentication and integrity verification, making authentication a core IPSec function.