Receiving Message #1

When the host receives the CFG_REQUEST (as specified in [RFC4306] section 3.15) for the INTERNAL_IP4_SERVER or INTERNAL_IP6_SERVER attribute, it MUST validate the message as also specified in [RFC4306] section 3.15. Additionally, the host SHOULD<31>:

  • See whether the server has an internal IPv4 address or an internal IPv6 address.

  • If either or both are present, add these attributes in CFG_REPLY.

Any failures in this exchange MUST NOT affect the state of the IKE_SA.