IP Security (IPsec) is a standards-based suite that encrypts and authenticates IP packets so networks can communicate securely over untrusted links. If you’re asking what is IP Security, it’s the protocol foundation for site-to-site and remote-access VPNs connecting branches, data centers, and clouds.
IPsec works at Layer 3 in transport or tunnel mode and uses IKE (v1/v2) to negotiate keys and Security Associations. In practice, teams rely on ESP (often with AES-GCM), NAT-Traversal, and Perfect Forward Secrecy to protect data while keeping performance predictable.
We often see IT leaders use IPsec to extend private networks over the internet, provide failover for private circuits, and underpin SD-WAN/SASE fabrics when both ends are under your control.
Key advantages include:
- Confidentiality & integrity: Encrypts data and prevents tampering.
- Interoperability: Open standards enable multi-vendor connectivity.
- Flexibility: Supports site-to-site, host-to-host, and remote access.
- Resilience: Dual tunnels, DPD, and failover keep links available.
Our take? IPsec is the dependable transport layer for connecting trusted sites securely—simple, proven, and widely supported.
Designing IPsec for real-world uptime and scale? Explore our Private Networking Guide for tunnel topologies, cipher choices, redundancy patterns, and how to blend IPsec with SD-WAN or dedicated underlays.
