Field Type,Meaning,Reference
0x0000,Crypto-NAK; authentication failure,[RFC5905]
0x0002,Reserved for historic reasons,[RFC9748]
0x0102,Reserved for historic reasons,[RFC9748]
0x0104,Unique Identifier,"[RFC8915, Section 5.3]"
0x0200,No-Operation Request,[RFC5906]
0x0201,Association Message Request,[RFC5906]
0x0202,Certificate Message Request,[RFC5906]
0x0203,Cookie Message Request,[RFC5906]
0x0204,Autokey Message Request,[RFC5906]
0x0204,NTS Cookie,"[RFC8915, Section 5.4]"
0x0205,Leapseconds Message Request,[RFC5906]
0x0206,Sign Message Request,[RFC5906]
0x0207,IFF Identity Message Request,[RFC5906]
0x0208,GQ Identity Message Request,[RFC5906]
0x0209,MV Identity Message Request,[RFC5906]
0x0302,Reserved for historic reasons,[RFC9748]
0x0304,NTS Cookie Placeholder,"[RFC8915, Section 5.5]"
0x0402,Reserved for historic reasons,[RFC9748]
0x0404,NTS Authenticator and Encrypted Extension Fields,"[RFC8915, Section 5.6]"
0x0502,Reserved for historic reasons,[RFC9748]
0x0602,Reserved for historic reasons,[RFC9748]
0x0702,Reserved for historic reasons,[RFC9748]
0x0802,Reserved for historic reasons,[RFC9748]
0x0902,Reserved for historic reasons,[RFC9748]
0x2005,UDP Checksum Complement,[RFC7821]
0x8002,Reserved for historic reasons,[RFC9748]
0x8102,Reserved for historic reasons,[RFC9748]
0x8200,No-Operation Response,[RFC5906]
0x8201,Association Message Response,[RFC5906]
0x8202,Certificate Message Response,[RFC5906]
0x8203,Cookie Message Response,[RFC5906]
0x8204,Autokey Message Response,[RFC5906]
0x8205,Leapseconds Message Response,[RFC5906]
0x8206,Sign Message Response,[RFC5906]
0x8207,IFF Identity Message Response,[RFC5906]
0x8208,GQ Identity Message Response,[RFC5906]
0x8209,MV Identity Message Response,[RFC5906]
0x8302,Reserved for historic reasons,[RFC9748]
0x8402,Reserved for historic reasons,[RFC9748]
0x8502,Reserved for historic reasons,[RFC9748]
0x8602,Reserved for historic reasons,[RFC9748]
0x8702,Reserved for historic reasons,[RFC9748]
0x8802,Reserved for historic reasons,[RFC9748]
0x8902,Reserved for historic reasons,[RFC9748]
0xC002,Reserved for historic reasons,[RFC9748]
0xC102,Reserved for historic reasons,[RFC9748]
0xC200,No-Operation Error Response,[RFC5906]
0xC201,Association Message Error Response,[RFC5906]
0xC202,Certificate Message Error Response,[RFC5906]
0xC203,Cookie Message Error Response,[RFC5906]
0xC204,Autokey Message Error Response,[RFC5906]
0xC205,Leapseconds Message Error Response,[RFC5906]
0xC206,Sign Message Error Response,[RFC5906]
0xC207,IFF Identity Message Error Response,[RFC5906]
0xC208,GQ Identity Message Error Response,[RFC5906]
0xC209,MV Identity Message Error Response,[RFC5906]
0xC302,Reserved for historic reasons,[RFC9748]
0xC402,Reserved for historic reasons,[RFC9748]
0xC502,Reserved for historic reasons,[RFC9748]
0xC602,Reserved for historic reasons,[RFC9748]
0xC702,Reserved for historic reasons,[RFC9748]
0xC802,Reserved for historic reasons,[RFC9748]
0xC902,Reserved for historic reasons,[RFC9748]
0xF000-0xFFFF,Reserved for Private or Experimental Use,[RFC9748]