2003-11-03 2026-03-10 For the Civic Address Types Registry , please see: http://www.iana.org/assignments/civic-address-types-registry Standards Action 0 Reserved 1 SOLICIT 2 ADVERTISE 3 REQUEST 4 CONFIRM 5 RENEW 6 REBIND 7 REPLY 8 RELEASE 9 DECLINE 10 RECONFIGURE 11 INFORMATION-REQUEST 12 RELAY-FORW 13 RELAY-REPL 14 LEASEQUERY 15 LEASEQUERY-REPLY 16 LEASEQUERY-DONE 17 LEASEQUERY-DATA 18 RECONFIGURE-REQUEST 19 RECONFIGURE-REPLY 20 DHCPV4-QUERY 21 DHCPV4-RESPONSE 22 ACTIVELEASEQUERY 23 STARTTLS 24 BNDUPD 25 BNDREPLY 26 POOLREQ 27 POOLRESP 28 UPDREQ 29 UPDREQALL 30 UPDDONE 31 CONNECT 32 CONNECTREPLY 33 DISCONNECT 34 STATE 35 CONTACT 36 ADDR-REG-INFORM 37 ADDR-REG-REPLY 38-255 Unassigned Expert Review and Standards Action Ted Lemon, Bernie Volz, Tomek Mrugalski For the "Client ORO" column: a "Yes" for an option means that the client includes this option code in the Option Request option (see Section 21.7 of ) if it desires that configuration information; a "No" means that the option MUST NOT be included (and servers SHOULD silently ignore that option code if it appears in a client's Option Request option). 0 Reserved 1 OPTION_CLIENTID No Yes 2 OPTION_SERVERID No Yes 3 OPTION_IA_NA No No 4 OPTION_IA_TA No No Obsolete 5 OPTION_IAADDR No No 6 OPTION_ORO No Yes 7 OPTION_PREFERENCE No Yes 8 OPTION_ELAPSED_TIME No Yes 9 OPTION_RELAY_MSG No Yes 10 Unassigned No Yes 11 OPTION_AUTH No Yes 12 OPTION_UNICAST No Yes Obsolete 13 OPTION_STATUS_CODE No Yes 14 OPTION_RAPID_COMMIT No Yes 15 OPTION_USER_CLASS No Yes 16 OPTION_VENDOR_CLASS No No 17 OPTION_VENDOR_OPTS Optional No 18 OPTION_INTERFACE_ID No Yes 19 OPTION_RECONF_MSG No Yes 20 OPTION_RECONF_ACCEPT No Yes 21 OPTION_SIP_SERVER_D Yes Yes 22 OPTION_SIP_SERVER_A Yes Yes 23 OPTION_DNS_SERVERS Yes Yes 24 OPTION_DOMAIN_LIST Yes Yes 25 OPTION_IA_PD No No 26 OPTION_IAPREFIX No No 27 OPTION_NIS_SERVERS Yes Yes 28 OPTION_NISP_SERVERS Yes Yes 29 OPTION_NIS_DOMAIN_NAME Yes Yes 30 OPTION_NISP_DOMAIN_NAME Yes Yes 31 OPTION_SNTP_SERVERS Yes Yes 32 OPTION_INFORMATION_REFRESH_TIME Required for Information-request Yes 33 OPTION_BCMCS_SERVER_D Yes Yes 34 OPTION_BCMCS_SERVER_A Yes Yes 35 Unassigned Yes Yes 36 OPTION_GEOCONF_CIVIC Yes Yes 37 OPTION_REMOTE_ID No Yes 38 OPTION_SUBSCRIBER_ID No Yes 39 OPTION_CLIENT_FQDN Yes Yes 40 OPTION_PANA_AGENT Yes Yes 41 OPTION_NEW_POSIX_TIMEZONE Yes Yes 42 OPTION_NEW_TZDB_TIMEZONE Yes Yes 43 OPTION_ERO No Yes 44 OPTION_LQ_QUERY No Yes 45 OPTION_CLIENT_DATA No Yes 46 OPTION_CLT_TIME No Yes 47 OPTION_LQ_RELAY_DATA No Yes 48 OPTION_LQ_CLIENT_LINK No Yes 49 OPTION_MIP6_HNIDF Yes Yes 50 OPTION_MIP6_VDINF Yes Yes 51 OPTION_V6_LOST Yes Yes 52 OPTION_CAPWAP_AC_V6 Yes Yes 53 OPTION_RELAY_ID No Yes 54 OPTION-IPv6_Address-MoS Yes Yes 55 OPTION-IPv6_FQDN-MoS Yes Yes 56 OPTION_NTP_SERVER Yes Yes 57 OPTION_V6_ACCESS_DOMAIN Yes Yes 58 OPTION_SIP_UA_CS_LIST Yes Yes 59 OPT_BOOTFILE_URL Yes Yes 60 OPT_BOOTFILE_PARAM Yes Yes 61 OPTION_CLIENT_ARCH_TYPE No Yes 62 OPTION_NII Yes Yes 63 OPTION_GEOLOCATION Yes Yes 64 OPTION_AFTR_NAME Yes Yes 65 OPTION_ERP_LOCAL_DOMAIN_NAME Yes Yes 66 OPTION_RSOO No Yes 67 OPTION_PD_EXCLUDE Yes Yes 68 OPTION_VSS No Yes 69 OPTION_MIP6_IDINF Yes Yes 70 OPTION_MIP6_UDINF Yes Yes 71 OPTION_MIP6_HNP Yes Yes 72 OPTION_MIP6_HAA Yes Yes 73 OPTION_MIP6_HAF Yes Yes 74 OPTION_RDNSS_SELECTION Yes Yes 75 OPTION_KRB_PRINCIPAL_NAME Yes Yes 76 OPTION_KRB_REALM_NAME Yes Yes 77 OPTION_KRB_DEFAULT_REALM_NAME Yes Yes 78 OPTION_KRB_KDC Yes Yes 79 OPTION_CLIENT_LINKLAYER_ADDR No Yes 80 OPTION_LINK_ADDRESS No Yes 81 OPTION_RADIUS No Yes 82 OPTION_SOL_MAX_RT Required for Solicit Yes 83 OPTION_INF_MAX_RT Required for Information-request Yes 84 OPTION_ADDRSEL Yes Yes 85 OPTION_ADDRSEL_TABLE Yes Yes 86 OPTION_V6_PCP_SERVER Yes No 87 OPTION_DHCPV4_MSG No Yes 88 OPTION_DHCP4_O_DHCP6_SERVER Yes Yes 89 OPTION_S46_RULE No No 90 OPTION_S46_BR Yes No 91 OPTION_S46_DMR No Yes 92 OPTION_S46_V4V6BIND No Yes 93 OPTION_S46_PORTPARAMS No Yes 94 OPTION_S46_CONT_MAPE Yes No 95 OPTION_S46_CONT_MAPT Yes Yes 96 OPTION_S46_CONT_LW Yes Yes 97 OPTION_4RD Yes Yes 98 OPTION_4RD_MAP_RULE Yes Yes 99 OPTION_4RD_NON_MAP_RULE Yes Yes 100 OPTION_LQ_BASE_TIME No Yes 101 OPTION_LQ_START_TIME No Yes 102 OPTION_LQ_END_TIME No Yes 103 DHCP Captive-Portal Yes Yes 104 OPTION_MPL_PARAMETERS Yes No 105 OPTION_ANI_ATT No Yes 106 OPTION_ANI_NETWORK_NAME No Yes 107 OPTION_ANI_AP_NAME No Yes 108 OPTION_ANI_AP_BSSID No Yes 109 OPTION_ANI_OPERATOR_ID No Yes 110 OPTION_ANI_OPERATOR_REALM No Yes 111 OPTION_S46_PRIORITY Yes Yes 112 OPTION_MUD_URL_V6 No Yes 113 OPTION_V6_PREFIX64 Yes No 114 OPTION_F_BINDING_STATUS No Yes 115 OPTION_F_CONNECT_FLAGS No Yes 116 OPTION_F_DNS_REMOVAL_INFO No Yes 117 OPTION_F_DNS_HOST_NAME No Yes 118 OPTION_F_DNS_ZONE_NAME No Yes 119 OPTION_F_DNS_FLAGS No Yes 120 OPTION_F_EXPIRATION_TIME No Yes 121 OPTION_F_MAX_UNACKED_BNDUPD No Yes 122 OPTION_F_MCLT No Yes 123 OPTION_F_PARTNER_LIFETIME No Yes 124 OPTION_F_PARTNER_LIFETIME_SENT No Yes 125 OPTION_F_PARTNER_DOWN_TIME No Yes 126 OPTION_F_PARTNER_RAW_CLT_TIME No Yes 127 OPTION_F_PROTOCOL_VERSION No Yes 128 OPTION_F_KEEPALIVE_TIME No Yes 129 OPTION_F_RECONFIGURE_DATA No Yes 130 OPTION_F_RELATIONSHIP_NAME No Yes 131 OPTION_F_SERVER_FLAGS No Yes 132 OPTION_F_SERVER_STATE No Yes 133 OPTION_F_START_TIME_OF_STATE No Yes 134 OPTION_F_STATE_EXPIRATION_TIME No Yes 135 OPTION_RELAY_PORT No Yes 136 OPTION_V6_SZTP_REDIRECT Yes Yes 137 OPTION_S46_BIND_IPV6_PREFIX Yes Yes 138 OPTION_IA_LL No No 139 OPTION_LLADDR No No 140 OPTION_SLAP_QUAD No Yes 141 OPTION_V6_DOTS_RI Yes Yes 142 OPTION_V6_DOTS_ADDRESS Yes Yes 143 OPTION-IPv6_Address-ANDSF Yes Yes 144 OPTION_V6_DNR Yes No 145 OPTION_REGISTERED_DOMAIN Yes No RFC9527, Section 4.1 146 OPTION_FORWARD_DIST_MANAGER Yes Yes RFC9527, Section 4.2 147 OPTION_REVERSE_DIST_MANAGER Yes Yes RFC9527, Section 4.3 148 OPTION_ADDR_REG_ENABLE Yes Yes 149 OPTION_IA_SRV6_LOCATOR No No 150 OPTION_IALOCATOR No No 151-65535 Unassigned For each enterprise-number, there MUST only be a single instance. See for details. Standards Action 0 Success 1 UnspecFail 2 NoAddrsAvail 3 NoBinding 4 NotOnLink 5 UseMulticast Obsolete 6 NoPrefixAvail 7 UnknownQueryType 8 MalformedQuery 9 NotConfigured 10 NotAllowed 11 QueryTerminated 12 DataMissing 13 CatchUpComplete 14 NotSupported 15 TLSConnectionRefused 16 AddressInUse 17 ConfigurationConflict 18 MissingBindingInformation 19 OutdatedBindingInformation 20 ServerShuttingDown 21 DNSUpdateNotSupported 22 ExcessiveTimeSkew 23 NoSRv6LocatorAvail 24-65535 Unassigned Standards Action 1 DUID-LLT 2 DUID-EN 3 DUID-LL 4 DUID-UUID Standards Action 0 Reserved 1 QUERY_BY_ADDRESS 2 QUERY_BY_CLIENTID 3 QUERY_BY_RELAY_ID 4 QUERY_BY_LINK_ADDRESS 5 QUERY_BY_REMOTE_ID 6-255 Unassigned Standards Action 0 Reserved 1 IS 2 CS 3 ES 4-65534 Unassigned 65535 Reserved Expert Review Vincent Zimmer, Bernie Volz, Tomek Mrugalski 0x00 0x00 x86 BIOS 0x00 0x01 NEC/PC98 (DEPRECATED) 0x00 0x02 Itanium 0x00 0x03 DEC Alpha (DEPRECATED) 0x00 0x04 Arc x86 (DEPRECATED) 0x00 0x05 Intel Lean Client (DEPRECATED) 0x00 0x06 x86 UEFI 0x00 0x07 x64 UEFI 0x00 0x08 EFI Xscale (DEPRECATED) 0x00 0x09 EBC 0x00 0x0a ARM 32-bit UEFI 0x00 0x0b ARM 64-bit UEFI 0x00 0x0c PowerPC Open Firmware 0x00 0x0d PowerPC ePAPR 0x00 0x0e POWER OPAL v3 0x00 0x0f x86 uefi boot from http 0x00 0x10 x64 uefi boot from http 0x00 0x11 ebc boot from http 0x00 0x12 arm uefi 32 boot from http 0x00 0x13 arm uefi 64 boot from http 0x00 0x14 pc/at bios boot from http 0x00 0x15 arm 32 uboot 0x00 0x16 arm 64 uboot 0x00 0x17 arm uboot 32 boot from http 0x00 0x18 arm uboot 64 boot from http 0x00 0x19 RISC-V 32-bit UEFI 0x00 0x1a RISC-V 32-bit UEFI boot from http 0x00 0x1b RISC-V 64-bit UEFI 0x00 0x1c RISC-V 64-bit UEFI boot from http 0x00 0x1d RISC-V 128-bit UEFI 0x00 0x1e RISC-V 128-bit UEFI boot from http 0x00 0x1f s390 Basic 0x00 0x20 s390 Extended 0x00 0x21 MIPS 32-bit UEFI 0x00 0x22 MIPS 64-bit UEFI 0x00 0x23 Sunway 32-bit UEFI 0x00 0x24 Sunway 64-bit UEFI 0x00 0x25 LoongArch 32-bit UEFI 0x00 0x26 LoongArch 32-bit UEFI boot from http 0x00 0x27 LoongArch 64-bit UEFI 0x00 0x28 LoongArch 64-bit UEFI boot from http 0x00 0x29 arm rpiboot 0x00 0x2a-0xff 0xff Unassigned IETF Review 65 OPTION_ERP_LOCAL_DOMAIN_NAME IETF Review See the VSS Type Options registry at IETF Review 1 NTP_SUBOPTION_SRV_ADDR 2 NTP_SUBOPTION_MC_ADDR 3 NTP_SUBOPTION_SRV_FQDN Expert Review Bernie Volz, Tomek Mrugalski 26 Vendor-Specific 123 Delegated-IPv6-Prefix 144 DS-Lite-Tunnel-Name 168 Framed-IPv6-Address 169 DNS-Server-IPv6-Address 171 Delegated-IPv6-Prefix-Pool 172 Stateful-IPv6-Address-Pool 245.3 DHCPv6-Options IETF Review 64 DS-Lite 88 DHCPv4 over DHCPv6 94 MAP-E 95 MAP-T 96 Lightweight 4over6 RFC Required 0 DNS over mutually authenticated TLS DomTLS 1-15 Unassigned Expert Review Alan DeKok, Mohamed Boucadair 144 OPTION_V6_DNR Dong Wei mailto:dong.wei&arm.com 2022-06-24 Hendrik Brueckner mailto:brueckner&de.ibm.com 2023-07-25 Jeremy Kerr mailto:jeremy.kerr&au.ibm.com 2014-04-04 Jiading Zhang mailto:jdzhang&zd-tech.com.cn 2020-03-12 Joseph Shifflett mailto:joseph.shifflett&hp.com 2015-04-03 LI Chao mailto:lichao&loongson.cn 2021-10-26 Peter Harper mailto:peter.harper&raspberrypi.com 2021-12-23 Samer El-Haj-Mahmoud mailto:elhaj&hp.com 2014-06-04 Thomas Huth mailto:thuth&de.ibm.com 2012-06-06