Freedom251 › Business VPN Software
strongSwan
by strongSwan
What strongSwan is
strongSwan is free VPN software from the strongSwan project, founded in 2005. It implements Internet Key Exchange protocols for policy-based and route-based IPsec connections, supporting IKEv1, IKEv2, IPv6 tunnel and transport connections, MOBIKE, NAT traversal, and fragmented IKEv2 messages. Authentication can use EAP methods, X.509 certificates, pre-shared keys, or multiple IKEv2 authentication exchanges. A plugin system extends cryptographic algorithms, credentials, authentication, configuration, and access to IPsec and network stacks. Cryptography includes NIST elliptic-curve groups, X25519, Ed25519, classic exchanges, and post-quantum options including ML-KEM. Private keys and certificates can use smartcards through PKCS #11 or a TPM 2.0. It supports Linux, Android, FreeBSD, macOS, iOS, and Windows, with NetworkManager integration for Linux desktops and an Android app. Downloads include packages, source archives, a Docker image, and the app. The GPLv2 open-source plan costs nothing.
Who it suits
It suits administrators needing policy-based or route-based IPsec VPNs across desktop, mobile, and server platforms. Its advanced administration, audit logs, authentication choices, and device-posture support fit controlled network deployments.
What it does well
- Supports IKEv1, IKEv2, IPv6, MOBIKE, and NAT traversal
- Works across Linux, Android, FreeBSD, macOS, iOS, and Windows
- Plugin system extends cryptography and authentication
- Supports smartcards and TPM 2.0 key protection
- Free GPLv2 open-source plan
What to know first
- Core developer does not offer commercial configuration support
- Some components may require a commercial non-GPL license
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| GPLv2 open-source license | Open-source GPLv2; most components also have an optional commercial non-GPL license | Free |
| Commercial license and support | Commercial non-GPL license available for most components; optional support has two response-time/SLA levels | On request |
As strongswan.org lists them, read 8 Oct 2026. The maker's own page has the final word.
Verdict
strongSwan provides a broad IPsec VPN implementation with extensive authentication, cryptography, and platform support. Its free GPLv2 plan is useful for organizations that can manage deployment themselves, while commercial licensing and support are separate options.
Facts from strongSwan's own pages
- Access model
- vpn · strongswan.org, 22 Sept 2026
- Admin control level
- advanced · strongswan.org, 22 Sept 2026
- Audit logs
- Yes · strongswan.org, 22 Sept 2026
- Authentication
- Authentication options include EAP methods, X.509 certificates, pre-shared keys, and IKEv2 multiple authentication exchanges. · strongswan.org, 8 Oct 2026
- Cryptography
- It supports NIST elliptic-curve groups, X25519, Ed25519, and multiple classic and post-quantum key exchanges, including ML-KEM. · strongswan.org, 8 Oct 2026
- Device posture
- Yes · strongswan.org, 22 Sept 2026
- Distribution
- The download page links to distribution binary packages, source archives, a Docker image for trying the software, and the Android app. · strongswan.org, 8 Oct 2026
- Founded
- 2005 · strongswan.org, 28 Sept 2026
- Free plan
- Yes · strongswan.org, 22 Sept 2026
- IKE protocols
- It supports IKEv2 and IKEv1, IPv6 tunnel and transport connections, MOBIKE, NAT traversal, and IKEv2 message fragmentation. · strongswan.org, 8 Oct 2026
- Integrations
- A NetworkManager plugin integrates strongSwan with Linux desktops, and an Android app is available. · strongswan.org, 8 Oct 2026
- Key protection
- Private keys and certificates can be stored on smartcards through PKCS #11 or protected by a TPM 2.0. · strongswan.org, 8 Oct 2026
- Modularity
- Its plugin system can add cryptographic algorithms, credentials, authentication methods, configurations, and access to IPsec and network stacks. · strongswan.org, 8 Oct 2026
- Notable support limit
- The listed core developer offers development work and licensing, but not commercial configuration support. · strongswan.org, 8 Oct 2026
- Ownership
- The project page says secunet Security Networks AG acquired strongSwan's intellectual property rights in June 2022. · strongswan.org, 8 Oct 2026
- Platforms
- The project says it runs on Linux and has been ported to Android, FreeBSD, macOS, iOS, and Windows. · strongswan.org, 8 Oct 2026
- Project history
- strongSwan launched in 2005 as a fork of the discontinued FreeS/WAN project. · strongswan.org, 8 Oct 2026
- Purpose
- strongSwan implements Internet Key Exchange protocols to secure IP traffic in policy-based and route-based IPsec VPN scenarios. · strongswan.org, 8 Oct 2026
- Release signing
- The project says releases and security patches are signed with its published PGP key. · strongswan.org, 8 Oct 2026
- Security advisories
- The project publishes vulnerability advisories and machine-readable OSV records, with patches linked from advisories. · strongswan.org, 8 Oct 2026
- Site-to-site networking
- Yes · strongswan.org, 22 Sept 2026
- Support
- Free support includes documentation, GitHub Discussions, and an IRC channel; commercial support is also available from listed providers. · strongswan.org, 8 Oct 2026
- Supported platforms
- Linux,Android,FreeBSD,macOS,iOS,Windows · strongswan.org, 22 Sept 2026
Where strongSwan stands on Freedom251
- Business VPN Software#29 of 94
- Virtual Private Network Software#21 of 54
- Connectivity Solutions#9 of 23