Selectors
Maps SA with security policy in SPD
Extracted from network and transport layer headers
Source Address: can be a wild card, a range of addresses, a network prefix or a specific host
Destination Address: can be a wild card, a range of addresses, a network or a specific host
Name: identify a policy tied to a valid user or system; used during IKE negotiation, not during packet processing
Protocol: specifies transport protocol whenever it is accessible.
Upper Layer Ports: the upper layer ports represent the src and dst ports to which the policy is applicable