Couchbase deployments often require secure communications between nodes, which can be accomplished using Internet Protocol Security (IPsec), a protocol suite that authenticates and encrypts IP packets. The article provides a guide for Couchbase Administrators to configure IPsec in transport mode, which is suitable for securing communication across nodes within the same network. Transport mode is preferred over tunnel mode for Couchbase clusters due to its practicality and ease of setup. The guide outlines the installation and configuration of OpenSwan on a Linux system, detailing steps such as modifying configuration files and setting up a pre-shared key for secure connections. The article emphasizes the importance of enabling Perfect Forward Secrecy for improved security and provides instructions for testing the setup to ensure proper communication between nodes.