Dell PowerEdge FN I/O Module Command Line Reference Guide 9.10(0.0)

Internet protocol security (IPSec) is an end-to-end security scheme for securing IP communications by authenticating and encrypting all packets in a session. Use IPSec between hosts, gateways, or hosts and gateways.

Transport mode provides IP packet payload protection using ESP. You can use ESP alone or in combination with AH to provide additional authentication. AH protects data from modification but does not provide confidentiality.

SA is the configuration information that specifies the type of security provided to the IPSec flow. The SA is a set of algorithms and keys used to authenticate and encrypt the traffic flow. The AH and ESP use SA to provide traffic protection for the IPSec flow.