2005-06-02 2026-03-02 Standards Action 0 Reserved 1 SSH_MSG_DISCONNECT 2 SSH_MSG_IGNORE 3 SSH_MSG_UNIMPLEMENTED 4 SSH_MSG_DEBUG 5 SSH_MSG_SERVICE_REQUEST 6 SSH_MSG_SERVICE_ACCEPT 7 SSH_MSG_EXT_INFO 8 SSH_MSG_NEWCOMPRESS 9-19 Unassigned (Transport layer generic) 20 SSH_MSG_KEXINIT 21 SSH_MSG_NEWKEYS 22-29 Unassigned (Algorithm negotiation) 30-49 Reserved (key exchange method specific) 50 SSH_MSG_USERAUTH_REQUEST 51 SSH_MSG_USERAUTH_FAILURE 52 SSH_MSG_USERAUTH_SUCCESS 53 SSH_MSG_USERAUTH_BANNER 54-59 Unassigned (User authentication generic) 60 SSH_MSG_USERAUTH_INFO_REQUEST 61 SSH_MSG_USERAUTH_INFO_RESPONSE 62-79 Reserved (User authentication method specific) 80 SSH_MSG_GLOBAL_REQUEST 81 SSH_MSG_REQUEST_SUCCESS 82 SSH_MSG_REQUEST_FAILURE 83-89 Unassigned (Connection protocol generic) 90 SSH_MSG_CHANNEL_OPEN 91 SSH_MSG_CHANNEL_OPEN_CONFIRMATION 92 SSH_MSG_CHANNEL_OPEN_FAILURE 93 SSH_MSG_CHANNEL_WINDOW_ADJUST 94 SSH_MSG_CHANNEL_DATA 95 SSH_MSG_CHANNEL_EXTENDED_DATA 96 SSH_MSG_CHANNEL_EOF 97 SSH_MSG_CHANNEL_CLOSE 98 SSH_MSG_CHANNEL_REQUEST 99 SSH_MSG_CHANNEL_SUCCESS 100 SSH_MSG_CHANNEL_FAILURE 101-127 Unassigned (Channel related messages) 128-191 Reserved (for client protocols) 192-255 Reserved for Private Use (local extensions) SSH_MSG_DISCONNECT 'description' and 'reason code' values Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. 0x00000001-0xFDFFFFFF Expert Review 0xFE000000-0xFFFFFFFF Reserved for Private Use Peter Yee, Markus Stenberg 0x00000000 Reserved 0x00000001 SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 0x00000002 SSH_DISCONNECT_PROTOCOL_ERROR 0x00000003 SSH_DISCONNECT_KEY_EXCHANGE_FAILED 0x00000004 SSH_DISCONNECT_RESERVED 0x00000005 SSH_DISCONNECT_MAC_ERROR 0x00000006 SSH_DISCONNECT_COMPRESSION_ERROR 0x00000007 SSH_DISCONNECT_SERVICE_NOT_AVAILABLE 0x00000008 SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 0x00000009 SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 0x0000000A SSH_DISCONNECT_CONNECTION_LOST 0x0000000B SSH_DISCONNECT_BY_APPLICATION 0x0000000C SSH_DISCONNECT_TOO_MANY_CONNECTIONS 0x0000000D SSH_DISCONNECT_AUTH_CANCELLED_BY_USER 0x0000000E SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 0x0000000F SSH_DISCONNECT_ILLEGAL_USER_NAME 0x00000010-0xFDFFFFFF Unassigned 0xFE000000-0xFFFFFFFF Reserved for Private Use 'reason code' values and 'description' values Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. 0x00000001-0xFDFFFFFF Expert Review 0xFE000000-0xFFFFFFFF Reserved for Private Use Peter Yee, Markus Stenberg 0x00000000 Reserved 0x00000001 SSH_OPEN_ADMINISTRATIVELY_PROHIBITED 0x00000002 SSH_OPEN_CONNECT_FAILED 0x00000003 SSH_OPEN_UNKNOWN_CHANNEL_TYPE 0x00000004 SSH_OPEN_RESOURCE_SHORTAGE 0x00000005-0xFDFFFFFF Unassigned 0xFE000000-0xFFFFFFFF Reserved for Private Use 'data_type_code' values and 'data' values Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. 0x00000001-0xFDFFFFFF Expert Review 0xFE000000-0xFFFFFFFF Reserved for Private Use Peter Yee, Markus Stenberg 0x00000000 Reserved 0x00000001 SSH_EXTENDED_DATA_STDERR 0x00000002-0xFDFFFFFF Unassigned 0xFE000000-0xFFFFFFFF Reserved for Private Use Expert Review Peter Yee, Markus Stenberg opcode and argument values which make up the "encoded terminal modes" values Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. 0 TTY_OP_END Indicates end of options. 1 VINTR Interrupt character; 255 if none. Similarly for the other characters. Not all of these characters are supported on all systems. Section 8 2 VQUIT The quit character (sends SIGQUIT signal on POSIX systems). Section 8 3 VERASE Erase the character to left of the cursor. Section 8 4 VKILL Kill the current input line. Section 8 5 VEOF End-of-file character (sends EOF from the terminal). Section 8 6 VEOL End-of-line character in addition to carriage return and/or linefeed. Section 8 7 VEOL2 Additional end-of-line character. Section 8 8 VSTART Continues paused output (normally control-Q). Section 8 9 VSTOP Pauses output (normally control-S). Section 8 10 VSUSP Suspends the current program. Section 8 11 VDSUSP Another suspend character. Section 8 12 VREPRINT Reprints the current input line. Section 8 13 VWERASE Erases a word left of cursor. Section 8 14 VLNEXT Enter the next character typed literally, even if it is a special character Section 8 15 VFLUSH Character to flush output. Section 8 16 VSWTCH Switch to a different shell layer. Section 8 17 VSTATUS Prints system status line (load, command, pid, etc). Section 8 18 VDISCARD Toggles the flushing of terminal output. Section 8 19-29 Unassigned 30 IGNPAR The ignore parity flag. The parameter SHOULD be 0 if this flag is FALSE, and 1 if it is TRUE. Section 8 31 PARMRK Mark parity and framing errors. Section 8 32 INPCK Enable checking of parity errors. Section 8 33 ISTRIP Strip 8th bit off characters. Section 8 34 INLCR Map NL into CR on input. Section 8 35 IGNCR Ignore CR on input. Section 8 36 ICRNL Map CR to NL on input. Section 8 37 IUCLC Translate uppercase characters to lowercase. Section 8 38 IXON Enable output flow control. Section 8 39 IXANY Any char will restart after stop. Section 8 40 IXOFF Enable input flow control. Section 8 41 IMAXBEL Ring bell on input queue full. Section 8 42 IUTF8 Terminal input and output is assumed to be encoded in UTF-8. 43-49 Unassigned 50 ISIG Enable signals INTR, QUIT, [D]SUSP. Section 8 51 ICANON Canonicalize input lines. Section 8 52 XCASE Enable input and output of uppercase characters by preceding their lowercase equivalents with "\". Section 8 53 ECHO Enable echoing. Section 8 54 ECHOE Visually erase chars. Section 8 55 ECHOK Kill character discards current line. Section 8 56 ECHONL Echo NL even if ECHO is off. Section 8 57 NOFLSH Don't flush after interrupt. Section 8 58 TOSTOP Stop background jobs from output. Section 8 59 IEXTEN Enable extensions. Section 8 60 ECHOCTL Echo control characters as ^(Char). Section 8 61 ECHOKE Visual erase for line kill. Section 8 62 PENDIN Retype pending input. Section 8 63-69 Unassigned 70 OPOST Enable output processing. Section 8 71 OLCUC Convert lowercase to uppercase. Section 8 72 ONLCR Map NL to CR-NL. Section 8 73 OCRNL Translate carriage return to newline (output). Section 8 74 ONOCR Translate newline to carriage return-newline (output). Section 8 75 ONLRET Newline performs a carriage return (output). Section 8 76-89 Unassigned 90 CS7 7 bit mode. Section 8 91 CS8 8 bit mode. Section 8 92 PARENB Parity enable. Section 8 93 PARODD Odd parity, else even. Section 8 94-127 Unassigned 128 TTY_OP_ISPEED Specifies the input baud rate in bits per second. Section 8 129 TTY_OP_OSPEED Specifies the output baud rate in bits per second. Section 8 130-255 Unassigned Expert Review Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. Peter Yee, Markus Stenberg ssh-userauth ssh-connection Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. publickey Section 7 password Section 8 hostbased Section 9 none Section 5.2 keyboard-interactive gssapi-with-mic gssapi-keyex gssapi external-keyx Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. session Section 6.1 x11 Section 6.3.2 forwarded-tcpip Section 7.2 direct-tcpip Section 7.2 agent-connect Section 5.3 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. tcpip-forward Section 7.1 cancel-tcpip-forward Section 7.1 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. pty-req Section 6.2 x11-req Section 6.3.1 env Section 6.4 shell Section 6.5 exec Section 6.5 subsystem Section 6.5 window-change Section 6.7 xon-xoff Section 6.8 signal Section 6.9 exit-status Section 6.10 exit-signal Section 6.10 break agent-req Section 5.2 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. ABRT ALRM FPE HUP ILL INT KILL PIPE QUIT SEGV TERM USR1 USR2 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. publickey snmp netconf rpki-rtr Expert Review Peter Yee, Markus Stenberg *All values beginning with the specified string and not containing "@". “OK to Implement” guidance entries for registrations that pre-date are found in Table 12 in Section 4 of . When this registry is modified, the YANG module "iana-ssh-key-exchange-algs" must be updated as defined in . Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. diffie-hellman-group-exchange-sha1 Section 4.1 SHOULD NOT diffie-hellman-group-exchange-sha256 Section 4.2 MAY diffie-hellman-group1-sha1 Section 8.1 SHOULD NOT diffie-hellman-group14-sha1 Section 8.2 MAY diffie-hellman-group14-sha256 MUST diffie-hellman-group15-sha512 MAY diffie-hellman-group16-sha512 SHOULD diffie-hellman-group17-sha512 MAY diffie-hellman-group18-sha512 MAY ecdh-sha2-* MAY ecmqv-sha2 MAY gss-group1-sha1-* SHOULD NOT gss-group14-sha1-* SHOULD NOT gss-gex-sha1-* SHOULD NOT gss- Section 2.6 reserved rsa1024-sha1 MUST NOT rsa2048-sha256 MAY ext-info-s Section 2 SHOULD ext-info-c Section 2 SHOULD gss-group14-sha256-* SHOULD gss-group15-sha512-* MAY gss-group16-sha512-* MAY gss-group17-sha512-* MAY gss-group18-sha512-* MAY gss-nistp256-sha256-* SHOULD gss-nistp384-sha384-* SHOULD gss-nistp521-sha512-* SHOULD gss-curve25519-sha256-* SHOULD gss-curve448-sha512-* MAY curve25519-sha256 SHOULD curve448-sha512 MAY ecdh-sha2-nistp256 SHOULD ecdh-sha2-nistp384 SHOULD ecdh-sha2-nistp521 SHOULD sntrup761x25519-sha512 SHOULD mlkem768nistp256-sha256 SHOULD mlkem1024nistp384-sha384 SHOULD mlkem768x25519-sha256 SHOULD mlkem512-sha256 MAY mlkem768-sha256 MAY mlkem1024-sha384 MAY Expert Review Peter Yee, Markus Stenberg When this registry is modified, the YANG module "iana-ssh-encryption-algs" must be updated as defined in . Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. 3des-cbc Section 6.3 blowfish-cbc Section 6.3 twofish256-cbc Section 6.3 twofish-cbc Section 6.3 twofish192-cbc Section 6.3 twofish128-cbc Section 6.3 aes256-cbc Section 6.3 aes192-cbc Section 6.3 aes128-cbc Section 6.3 serpent256-cbc Section 6.3 serpent192-cbc Section 6.3 serpent128-cbc Section 6.3 arcfour HISTORIC idea-cbc Section 6.3 cast128-cbc Section 6.3 none Section 6.3 des-cbc FIPS-46-3 HISTORIC, See page 4 arcfour128 HISTORIC arcfour256 HISTORIC aes128-ctr aes192-ctr aes256-ctr 3des-ctr blowfish-ctr twofish128-ctr twofish192-ctr twofish256-ctr serpent128-ctr serpent192-ctr serpent256-ctr idea-ctr cast128-ctr AEAD_AES_128_GCM Section 6.1 AEAD_AES_256_GCM Section 6.2 chacha20-poly1305 Expert Review Peter Yee, Markus Stenberg When this registry is modified, the YANG module "iana-ssh-mac-algs" must be updated as defined in . Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. hmac-sha1 Section 6.4 hmac-sha1-96 Section 6.4 hmac-md5 Section 6.4 hmac-md5-96 Section 6.4 none Section 6.4 AEAD_AES_128_GCM Section 6.1 AEAD_AES_256_GCM Section 6.2 hmac-sha2-256 Section 2 hmac-sha2-512 Section 2 Expert Review Peter Yee, Markus Stenberg *All values beginning with the specified string and not containing "@". When this registry is modified, the YANG module "iana-ssh-public-key-algs" must be updated as defined in . Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. ssh-dss ssh-dss Section 6.6 ssh-rsa ssh-rsa Section 6.6 rsa-sha2-256 ssh-rsa Section 3 rsa-sha2-512 ssh-rsa Section 3 spki-sign-rsa spki-sign-rsa Section 6.6 spki-sign-dss spki-sign-dss Section 6.6 pgp-sign-rsa pgp-sign-rsa Section 6.6 pgp-sign-dss pgp-sign-dss Section 6.6 null null Section 5 ecdsa-sha2-* ecdsa-sha2-* x509v3-ssh-dss x509v3-ssh-dss x509v3-ssh-rsa x509v3-ssh-rsa x509v3-rsa2048-sha256 x509v3-rsa2048-sha256 x509v3-ecdsa-sha2-* x509v3-ecdsa-sha2-* ssh-ed25519 ssh-ed25519 ssh-ed448 ssh-ed448 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. none Section 6.2 zlib Section 6.2 Expert Review Peter Yee, Markus Stenberg Tags beginning with x- Reserved for Private Use Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. subject Section 3.3.1 comment Section 3.3.2 Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. version add remove list listattributes Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. version status publickey attribute Expert Review Peter Yee, Markus Stenberg Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. comment comment-language command-override subsystem x11 shell exec agent env from port-forward reverse-forward 0-191 Standards Action 192-255 Reserved for Private Use 0 SSH_PUBLICKEY_SUCCESS 1 SSH_PUBLICKEY_ACCESS_DENIED 2 SSH_PUBLICKEY_STORAGE_EXCEEDED 3 SSH_PUBLICKEY_VERSION_NOT_SUPPORTED 4 SSH_PUBLICKEY_KEY_NOT_FOUND 5 SSH_PUBLICKEY_KEY_NOT_SUPPORTED 6 SSH_PUBLICKEY_KEY_ALREADY_PRESENT 7 SSH_PUBLICKEY_GENERAL_FAILURE 8 SSH_PUBLICKEY_REQUEST_NOT_SUPPORTED 9 SSH_PUBLICKEY_ATTRIBUTE_NOT_SUPPORTED 10-191 Standards Action 192-255 Reserved Expert Review Peter Yee, Markus Stenberg Names in the Extension Names table MUST follow the Conventions for Names defined in , Section 4.6.1. Registration requests should be sent to the mailing list described in . If approved, designated experts should notify IANA within three weeks. For assistance, please contact iana@iana.org. server-sig-algs Section 3.1 delay-compression Section 3.2 no-flow-control Section 3.3 elevation Section 3.4 agent-forward Section 5.1 Unassigned 0-239 Expert Review 240-255 Private Use 0 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 1 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 2 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 3 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 4 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 5 SSH_AGENT_FAILURE RFC-ietf-sshm-ssh-agent-16, Sections 3.1 and 6.1 6 SSH_AGENT_SUCCESS RFC-ietf-sshm-ssh-agent-16, Sections 3.1 and 6.1 7 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 8 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 9 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 10 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 11 SSH_AGENTC_REQUEST_IDENTITIES RFC-ietf-sshm-ssh-agent-16, Sections 3.5 and 6.1 12 SSH_AGENT_IDENTITIES_ANSWER RFC-ietf-sshm-ssh-agent-16, Sections 3.5 and 6.1 13 SSH_AGENTC_SIGN_REQUEST RFC-ietf-sshm-ssh-agent-16, Sections 3.6 and 6.1 14 SSH_AGENT_SIGN_RESPONSE RFC-ietf-sshm-ssh-agent-16, Sections 3.6 and 6.1 15 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 16 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 17 SSH_AGENTC_ADD_IDENTITY RFC-ietf-sshm-ssh-agent-16, Sections 3.2 and 6.1 18 SSH_AGENTC_REMOVE_IDENTITY RFC-ietf-sshm-ssh-agent-16, Sections 3.4 and 6.1 19 SSH_AGENTC_REMOVE_ALL_IDENTITIES RFC-ietf-sshm-ssh-agent-16, Sections 3.4 and 6.1 20 SSH_AGENTC_ADD_SMARTCARD_KEY RFC-ietf-sshm-ssh-agent-16, Sections 3.2.6 and 6.1 21 SSH_AGENTC_REMOVE_SMARTCARD_KEY RFC-ietf-sshm-ssh-agent-16, Sections 3.4 and 6.1 22 SSH_AGENTC_LOCK RFC-ietf-sshm-ssh-agent-16, Sections 3.7 and 6.1 23 SSH_AGENTC_UNLOCK RFC-ietf-sshm-ssh-agent-16, Sections 3.7 and 6.1 24 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.1.1 25 SSH_AGENTC_ADD_ID_CONSTRAINED RFC-ietf-sshm-ssh-agent-16, Sections 3.2 and 6.1 26 SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED RFC-ietf-sshm-ssh-agent-16, Sections 3.2.6 and 6.1 27 SSH_AGENTC_EXTENSION RFC-ietf-sshm-ssh-agent-16, Sections 3.8 and 6.1 28 SSH_AGENT_EXTENSION_FAILURE RFC-ietf-sshm-ssh-agent-16, Sections 3.8 and 6.1 29 SSH_AGENT_EXTENSION_RESPONSE RFC-ietf-sshm-ssh-agent-16, Sections 3.8 and 6.1 30-239 Unassigned 240-255 Reserved for Private Use RFC-ietf-sshm-ssh-agent-16, Section 6.1 Expert Review Unassigned 0 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.2 1 SSH_AGENT_CONSTRAIN_LIFETIME RFC-ietf-sshm-ssh-agent-16, Section 6.2 2 SSH_AGENT_CONSTRAIN_CONFIRM RFC-ietf-sshm-ssh-agent-16, Section 6.2 3-254 Unassigned 255 SSH_AGENT_CONSTRAIN_EXTENSION RFC-ietf-sshm-ssh-agent-16, Section 6.2 Expert Review Unassigned Expert Review Unassigned 0x01 Reserved RFC-ietf-sshm-ssh-agent-16, Section 6.3 0x02 SSH_AGENT_RSA_SHA2_256 RFC-ietf-sshm-ssh-agent-16, Section 6.3 0x04 SSH_AGENT_RSA_SHA2_512 RFC-ietf-sshm-ssh-agent-16, Section 6.3 Expert Review Unassigned query RFC-ietf-sshm-ssh-agent-16, Section 3.8.1