```html IPsec - Microsoft Learn

IPsec

Introduction to IPsec

IPsec (Internet Protocol Security) is a suite of protocols designed to secure IP communications by authenticating and encrypting each IP packet. It's a fundamental technology used to establish secure VPNs (Virtual Private Networks) and secure communications over public networks like the Internet.

Key Concepts

Transparent Mode

In Transparent Mode, IPsec modifies only the IP header of the packet, leaving the original payload untouched. This is useful for protecting traffic between hosts on the same network.

Transport Mode

In Transport Mode, IPsec protects only the payload of the IP packet. This is useful for securing communication between two hosts.

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