Phase 2 settings include settings for a security association (SA), which defines how data packets are secured when they are passed between two endpoints. The SA keeps all information necessary for the Firebox or XTM device to know what it should do with the traffic between the endpoints. Parameters in the SA can include:
To configure Phase 2 settings:
Perfect Forward Secrecy gives more protection to keys that are created in a session. Keys made with PFS are not made from a previous key. If a previous key is compromised after a session, your new session keys are secure. For more information, see About Diffie-Hellman Groups.
You can add more than one Phase 2 proposal in the Phase 2 Settings tab. However, you cannot add AH and ESP phase 2 proposals to the same Phase 2 configuration.
If you plan to use the IPSec pass-through feature, you must use a proposal with ESP (Encapsulating Security Payload) as the proposal method. IPSec pass-through supports ESP but not AH. For more information on IPSec pass-through, see About Global VPN Settings.