2.2.1 NAT-T Payload Types

Each ISAKMP message consists of a header and a variable number of payloads, each identified by a 1-octet payload type value in its Next Payload field, as specified in [RFC2408] section 3.1. NAT-T adds two new payload types: NAT Discovery (NAT-D) and NAT Original Address (NAT-OA). The payload type values for these payload types are specified in [RFC3947]. For more information about an alternative set of payload type values, see [DRAFT-NATT].

The NAT-D payload type values are as follows.

The supported NAT-OA payload types are as follows.