The HIP RRs require the following RDATA fields:

• <HIT length> (indicates the length in bytes of the HIT field, an 8-bit unsigned integer)
• <PK algorithm> (indicates the public key cryptographic algorithm and the implied public key field format, an 8-bit unsigned integer)
• <PK length> (indicates the length in bytes of the Public key field, a 16-bit unsigned integer in network byte order)
• <HIT> (stored as a binary value in network byte order)
• <public key> (RSA and DSA key types are supported, the public keys use the format defined for the IPSECKEY RR)
• <rendezvous servers> (optional, indicates one or more variable length wire-encoded domain names of rendezvous server(s), as described in Section 3.3 of RFC 1035)

More information on the HIP record is documented with RFC 5205.