Libreswan

Libreswan is an open-source IPsec implementation designed to provide secure and encrypted network communication over untrusted networks. Based on the Internet Protocol Security (IPsec) standards, it enables secure site-to-site and remote-access VPN connections using protocols such as IKE and supports strong authentication and encryption mechanisms. Libreswan is widely used for establishing secure tunnels between networks, servers, and remote clients, making it a reliable solution for protecting network traffic and implementing secure VPN infrastructures.

• Provides secure IPsec-based VPN connectivity for encrypted network communication.
• Supports Internet Key Exchange (IKE) for securely establishing and managing VPN connections.
• Supports strong encryption and authentication mechanisms for protecting network traffic.
• Enables site-to-site and remote-access VPN configurations.
• Integrates with Linux networking and firewall infrastructure for flexible deployment.
• Supports certificate-based and pre-shared-key authentication methods.
• Provides command-line tools and configuration files for managing IPsec connections and security policies.

Libreswan usage:

$ sudo su
$ apt update
$ cd /opt/libreswan

$ Verify installation:
# /usr/local/sbin/ipsec --version