2010-03-25 2026-01-07 Specification Required Kurt Kristof Teichel, Miroslav Lichvar, David Venhoek Codes beginning with the character "X" are reserved for experimentation and development. IANA cannot assign them. GOES Geosynchronous Orbit Environment Satellite GPS Global Position System GAL Galileo Positioning System PPS Generic pulse-per-second IRIG Inter-Range Instrumentation Group WWVB LF Radio WWVB Ft. Collins, CO 60 kHz DCF LF Radio DCF77 Mainflingen, DE 77.5 kHz HBG LF Radio HBG Prangins, HB 75 kHz MSF LF Radio MSF Anthorn, UK 60 kHz JJY LF Radio JJY Fukushima, JP 40 kHz, Saga, JP 60 kHz LORC MF Radio LORAN C station, 100 kHz TDF MF Radio Allouis, FR 162 kHz CHU HF Radio CHU Ottawa, Ontario WWV HF Radio WWV Ft. Collins, CO WWVH HF Radio WWVH Kauai, HI NIST NIST telephone modem ACTS NIST telephone modem USNO USNO telephone modem PTB European telephone modem DFM UTC(DFM) Specification Required Kurt Kristof Teichel, Miroslav Lichvar, David Venhoek Codes beginning with the character "X" are reserved for experimentation and development. IANA cannot assign them. ACST The association belongs to a unicast server AUTH Server authentication failed AUTO Autokey sequence failed BCST The association belongs to a broadcast server CRYP Cryptographic authentication or identification failed DENY Access denied by remote server DROP Lost peer in symmetric mode RSTR Access denied due to local policy INIT The association has not yet synchronized for the first time MCST The association belongs to a dynamically discovered server NKEY No key found. Either the key was never installed or is not trusted NTSN Network Time Security (NTS) negative-acknowledgment (NAK) RATE Rate exceeded. The server has temporarily denied access because the client exceeded the rate threshold RMOT Alteration of association from a remote host running ntpdc. STEP A step change in system time has occurred, but the association has not yet resynchronized Specification Required Field Types in the range 0xF000 through 0xFFFF, inclusive, are reserved for experimentation and development. IANA cannot assign them. Both NTS Cookie and Autokey Message Request have the same Field Type; in practice this is not a problem as the field semantics will be determined by other parts of the message. The "Reserved for historic reasons" is for differences between the original documentation and implementation of Autokey and marks the erroneous values as reserved, in case there is an implementation that used the registered values instead of what the original implementation used. Kurt Kristof Teichel, Miroslav Lichvar, David Venhoek 0x0000 Crypto-NAK; authentication failure 0x0002 Reserved for historic reasons 0x0102 Reserved for historic reasons 0x0104 Unique Identifier 0x010A Network Correction 0x0200 No-Operation Request 0x0201 Association Message Request 0x0202 Certificate Message Request 0x0203 Cookie Message Request 0x0204 Autokey Message Request 0x0204 NTS Cookie 0x0205 Leapseconds Message Request 0x0206 Sign Message Request 0x0207 IFF Identity Message Request 0x0208 GQ Identity Message Request 0x0209 MV Identity Message Request 0x0302 Reserved for historic reasons 0x0304 NTS Cookie Placeholder 0x0402 Reserved for historic reasons 0x0404 NTS Authenticator and Encrypted Extension Fields 0x0502 Reserved for historic reasons 0x0602 Reserved for historic reasons 0x0702 Reserved for historic reasons 0x0802 Reserved for historic reasons 0x0902 Reserved for historic reasons 0x2005 UDP Checksum Complement 0x8002 Reserved for historic reasons 0x8102 Reserved for historic reasons 0x8200 No-Operation Response 0x8201 Association Message Response 0x8202 Certificate Message Response 0x8203 Cookie Message Response 0x8204 Autokey Message Response 0x8205 Leapseconds Message Response 0x8206 Sign Message Response 0x8207 IFF Identity Message Response 0x8208 GQ Identity Message Response 0x8209 MV Identity Message Response 0x8302 Reserved for historic reasons 0x8402 Reserved for historic reasons 0x8502 Reserved for historic reasons 0x8602 Reserved for historic reasons 0x8702 Reserved for historic reasons 0x8802 Reserved for historic reasons 0x8902 Reserved for historic reasons 0xC002 Reserved for historic reasons 0xC102 Reserved for historic reasons 0xC200 No-Operation Error Response 0xC201 Association Message Error Response 0xC202 Certificate Message Error Response 0xC203 Cookie Message Error Response 0xC204 Autokey Message Error Response 0xC205 Leapseconds Message Error Response 0xC206 Sign Message Error Response 0xC207 IFF Identity Message Error Response 0xC208 GQ Identity Message Error Response 0xC209 MV Identity Message Error Response 0xC302 Reserved for historic reasons 0xC402 Reserved for historic reasons 0xC502 Reserved for historic reasons 0xC602 Reserved for historic reasons 0xC702 Reserved for historic reasons 0xC802 Reserved for historic reasons 0xC902 Reserved for historic reasons 0xF000-0xFFFF Reserved for Private or Experimental Use DFM A/S https://dfm.dk 2023-05-03 Jürgen Appel DFM A/S mailto:jap&dfm.dk 2023-05-03