1.3.9 IKE SA Correlation (IKEv2)

This extension allows two different IKEv2 IKE_SA to be correlated together. Assume that an IKE_SA has been established. This is called SAoriginal. At a later time, to ensure that the client credentials are still valid, but without tearing down the existing SA, a new IKE_SA (called SAcurrent) can be built to embed a new payload in this exchange that securely correlates this SA with the original SA.