It provides the mechanisms needed for discovering, accessing, and processing security policy information of hosts, subnets, or networks. Section 4 gives more details. Most of the burden of discovering and processing policy is placed on the initiator of a communications. Policy Servers MAY optionally perform policy resolution, to improve caching and accelerate communication establishment. To convince a security gateway or remote host to allow traffic through.
Local policy is expressed in a vendor-specific way.
Such statements MUST be securely stored and protected from tampering. Use of SPP in IPSP SPP is a security gateway and policy discovery protocol. It allows a host to determine what security gateways lie in the path to a specific destination, and what their security policies are. These credentials are then provided to the security gateway that forwarded the SPP query, and to the host that initiated the SPP protocol. For this, the end-host emulates the compliance checking process that the security gateway or remote host will perform when negotiating SAs.