IPsec delivers the following benefits:
Reduced key negotiation overhead and simplified maintenance by supporting the IKE protocol. IKE provides automatic key negotiation and automatic IPsec security association (SA) setup and maintenance.
Good compatibility. You can apply IPsec to all IP-based application systems and services without modifying them.
Encryption on a per-packet rather than per-flow basis. Per-packet encryption allows for flexibility and greatly enhances IP security.
See Also
What Is IPsec?