Internet Assigned Numbers Authority Border Gateway Protocol (BGP) Parameters Last Updated 2025-06-17 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registries Included Below • BGP Message Types • BGP Path Attributes • BGP Error (Notification) Codes • BGP Error Subcodes • Message Header Error subcodes • OPEN Message Error subcodes • UPDATE Message Error subcodes • BGP Finite State Machine Error Subcodes • BGP Cease NOTIFICATION message subcodes • BGP ROUTE-REFRESH Message Error subcodes • BGP Outbound Route Filtering (ORF) Types • BGP OPEN Optional Parameter Types • BGP Tunnel Encapsulation Attribute Tunnel Types • BGP Tunnel Encapsulation Attribute Sub-TLVs • BGP Layer 2 Encapsulation Types • BGP Layer 2 TLV Types • BGP AIGP Attribute Types • BGP Route Refresh Subcodes • P-Multicast Service Interface Tunnel (PMSI Tunnel) Tunnel Types • P-Multicast Service Interface (PMSI) Tunnel Attribute Flags • BGP MCAST-VPN Route Types • BGP Prefix-SID TLV Types • BGP Prefix-SID Label-Index TLV Flags • BGP Prefix-SID Originator SRGB TLV Flags • BGP Graceful Restart Flags • BGP Graceful Restart Flags for Address Family • SFP Attribute TLVs • SFP Association Type • SFC SPI/SI Representation Flags • BFD Mode • BFD Discriminator Optional TLV Type • SRv6 Service Sub-TLV Types • SRv6 Service Data Sub-Sub-TLV Types • BGP SRv6 Service SID Flags • Long-Lived Graceful Restart Flags for Address Family • BGP BIER TLV and Sub-TLV Types • BGP CAR NLRI Types • BGP CAR NLRI TLV Types BGP Message Types Registration Procedure(s) Standards Action Reference [RFC4271] Available Formats [IMG] CSV Value Name Reference 0 Reserved 1 OPEN [RFC4271] 2 UPDATE [RFC4271] 3 NOTIFICATION [RFC4271] 4 KEEPALIVE [RFC4271] 5 ROUTE-REFRESH [RFC2918] 6-255 Unassigned BGP Path Attributes Registration Procedure(s) Standards Action Reference [RFC4271] Available Formats [IMG] CSV Value Code Reference 0 Reserved 1 ORIGIN [RFC4271] 2 AS_PATH [RFC4271] 3 NEXT_HOP [RFC4271] 4 MULTI_EXIT_DISC [RFC4271] 5 LOCAL_PREF [RFC4271] 6 ATOMIC_AGGREGATE [RFC4271] 7 AGGREGATOR [RFC4271] 8 COMMUNITIES [RFC1997] 9 ORIGINATOR_ID [RFC4456] 10 CLUSTER_LIST [RFC4456] 11 DPA (deprecated) [Chen, E., Bates, T., "Destination Preference Attribute for BGP", Work in progress, March 1996.][RFC6938] ADVERTISER 12 (historic) [RFC1863][RFC4223][RFC6938] (deprecated) RCID_PATH / 13 CLUSTER_ID [RFC1863][RFC4223][RFC6938] (Historic) (deprecated) 14 MP_REACH_NLRI [RFC4760] 15 MP_UNREACH_NLRI [RFC4760] 16 EXTENDED [Eric_Rosen][draft-ramachandra-bgp-ext-communities-00][RFC4360] COMMUNITIES 17 AS4_PATH [RFC6793] 18 AS4_AGGREGATOR [RFC6793] SAFI Specific 19 Attribute (SSA) [Gargi_Nalawade][draft-kapoor-nalawade-idr-bgp-ssa-00][draft-nalawade-idr-mdt-safi-00][draft-wijnands-mt-discovery-00] (deprecated) Connector 20 Attribute [RFC6037] (deprecated) 21 AS_PATHLIMIT [draft-ietf-idr-as-pathlimit-02] (deprecated) 22 PMSI_TUNNEL [RFC6514] 23 Tunnel [RFC9012] Encapsulation 24 Traffic [RFC5543] Engineering IPv6 Address 25 Specific Extended [RFC5701] Community 26 AIGP [RFC7311] 27 PE Distinguisher [RFC6514] Labels BGP Entropy Label 28 Capability [RFC6790][RFC7447] Attribute (deprecated) 29 BGP-LS Attribute [RFC9552] 30 Deprecated [RFC8093] 31 Deprecated [RFC8093] 32 LARGE_COMMUNITY [RFC8092] 33 BGPsec_Path [RFC8205] BGP Community Container Attribute (TEMPORARY - registered 34 2017-07-28, [draft-ietf-idr-wide-bgp-communities-11] extension registered 2024-08-22, expires 2025-07-28) 35 Only to Customer [RFC9234] (OTC) BGP Domain Path (D-PATH) (TEMPORARY - registered 36 2019-07-08, [draft-ietf-bess-evpn-ipvpn-interworking-10] extension registered 2025-06-06, expires 2026-07-08) 37 SFP attribute [RFC9015] 38 BFD Discriminator [RFC9026] BGP Next Hop Dependent Capabilities (NHC) (TEMPORARY - registered 39 2022-12-20, [draft-ietf-idr-entropy-label-13] extension registered 2024-12-10, expires 2025-12-20) 40 BGP Prefix-SID [RFC8669] 41 BIER [RFC9793] Edge Metadata Path Attribute (TEMPORARY - 42 registered [draft-ietf-idr-5g-edge-service-metadata-27] 2025-04-23, expires 2026-04-23) 43-127 Unassigned 128 ATTR_SET [RFC6368] 129 Deprecated [RFC8093] 130-240 Unassigned 241 Deprecated [RFC8093] 242 Deprecated [RFC8093] 243 Deprecated [RFC8093] 244-254 Unassigned 255 Reserved for [RFC2042] development BGP Error (Notification) Codes Registration Procedure(s) Standards Action Reference [RFC4271][RFC7313] Available Formats [IMG] CSV Value Name Reference 0 Reserved 1 Message Header Error [RFC4271] 2 OPEN Message Error [RFC4271] 3 UPDATE Message Error [RFC4271] 4 Hold Timer Expired [RFC4271] 5 Finite State Machine Error [RFC4271] 6 Cease [RFC4271] 7 ROUTE-REFRESH Message Error [RFC7313] 8 Send Hold Timer Expired [RFC9687] 9 Loss of LSDB Synchronization [RFC-ietf-lsvr-bgp-spf-51] 10-255 Unassigned BGP Error Subcodes Registration Procedure(s) Standards Action Reference [RFC4271] Message Header Error subcodes Registration Procedure(s) Standards Action Reference [RFC4271] Available Formats [IMG] CSV Value Name Reference 0 Unspecific [RFC Errata 4493] 1 Connection Not Synchronized [RFC4271] 2 Bad Message Length [RFC4271] 3 Bad Message Type [RFC4271] 4-255 Unassigned OPEN Message Error subcodes Registration Procedure(s) Standards Action Reference [RFC4271] Available Formats [IMG] CSV Value Name Reference 0 Unspecific [RFC Errata 4493] 1 Unsupported Version Number [RFC4271] 2 Bad Peer AS [RFC4271] 3 Bad BGP Identifier [RFC4271] 4 Unsupported Optional Parameter [RFC4271] 5 [Deprecated] [RFC4271] 6 Unacceptable Hold Time [RFC4271] 7 Unsupported Capability [RFC5492] 8 Deprecated [RFC9234] 9 Deprecated [RFC9234] 10 Deprecated [RFC9234] 11 Role Mismatch [RFC9234] 12-255 Unassigned UPDATE Message Error subcodes Registration Procedure(s) Standards Action Reference [RFC4271] Available Formats [IMG] CSV Value Name Reference 0 Unspecific [RFC Errata 4493] 1 Malformed Attribute List [RFC4271] 2 Unrecognized Well-known Attribute [RFC4271] 3 Missing Well-known Attribute [RFC4271] 4 Attribute Flags Error [RFC4271] 5 Attribute Length Error [RFC4271] 6 Invalid ORIGIN Attribute [RFC4271] 7 [Deprecated] [RFC4271] 8 Invalid NEXT_HOP Attribute [RFC4271] 9 Optional Attribute Error [RFC4271] 10 Invalid Network Field [RFC4271] 11 Malformed AS_PATH [RFC4271] 12-255 Unassigned BGP Finite State Machine Error Subcodes Registration Procedure(s) Standards Action Reference [RFC6608] Available Formats [IMG] CSV Value Name Reference 0 Unspecified Error [RFC6608] 1 Receive Unexpected Message in OpenSent State [RFC6608] 2 Receive Unexpected Message in OpenConfirm State [RFC6608] 3 Receive Unexpected Message in Established State [RFC6608] 4-255 Unassigned BGP Cease NOTIFICATION message subcodes Registration Procedure(s) Standards Action or Early IANA Allocation process Reference [RFC4486] Available Formats [IMG] CSV Value Name Reference 0 Reserved 1 Maximum Number of Prefixes Reached [RFC4486] 2 Administrative Shutdown [RFC4486][RFC9003] 3 Peer De-configured [RFC4486] 4 Administrative Reset [RFC4486][RFC9003] 5 Connection Rejected [RFC4486] 6 Other Configuration Change [RFC4486] 7 Connection Collision Resolution [RFC4486] 8 Out of Resources [RFC4486] 9 Hard Reset [RFC8538] 10 BFD Down [RFC9384] 11-255 Unassigned BGP ROUTE-REFRESH Message Error subcodes Reference [RFC7313] Available Formats [IMG] CSV Range Registration Procedures 0-127 Standards Action 128-255 First Come First Served Value Name Reference 0 Reserved [RFC7313] 1 Invalid Message Length [RFC7313] 2-255 Unassigned BGP Outbound Route Filtering (ORF) Types Reference [RFC5291] Available Formats [IMG] CSV Range Registration Procedures Note 0-63 Standards Action 64-127 First Come First Served 128-255 Vendor-Specific IANA does not assign Value Description Reference 0 Reserved [RFC5291] 1-63 Unassigned 64 Address Prefix ORF [RFC5292] 65 CP-ORF [RFC7543] 66 VPN Prefix ORF [draft-ietf-idr-vpn-prefix-orf-06] 67-127 Unassigned 128-255 Reserved for Vendor-Specific [RFC5291] BGP OPEN Optional Parameter Types Registration Procedure(s) IETF Review Reference [RFC5492] Available Formats [IMG] CSV Value Name Reference 0 Reserved [RFC5492] 1 Authentication (deprecated) [RFC4271][RFC5492] 2 Capabilities [RFC5492] 3-254 Unassigned 255 Extended Length [RFC9072] BGP Tunnel Encapsulation Attribute Tunnel Types Reference [RFC9012] Note Moved to [https://www.iana.org/assignments/bgp-tunnel-encapsulation] per [RFC9012]. BGP Tunnel Encapsulation Attribute Sub-TLVs Reference [RFC9012] Note Moved to [https://www.iana.org/assignments/bgp-tunnel-encapsulation] per [RFC9012]. BGP Layer 2 Encapsulation Types Reference [RFC6624] Note When this registry is modified, the YANG module [iana-bgp-l2-encaps] must be updated as defined in [RFC9291]. Available Formats [IMG] CSV Range Registration Procedures 0-127 Expert Review 128-251 First Come First Served 252-255 Experimental Use Value Description Reference 0 Reserved [RFC6624] 1 Frame Relay [RFC4446] 2 ATM AAL5 SDU VCC transport [RFC4446] 3 ATM transparent cell transport [RFC4816] 4 Ethernet (VLAN) Tagged Mode [RFC4448] 5 Ethernet Raw Mode [RFC4448] 6 Cisco HDLC [RFC4618] 7 PPP [RFC4618] 8 SONET/SDH Circuit Emulation Service [RFC4842] 9 ATM n-to-one VCC cell transport [RFC4717] 10 ATM n-to-one VPC cell transport [RFC4717] 11 IP Layer 2 Transport [RFC3032] 12-14 Unassigned 15 Frame Relay Port mode [RFC4619] 16 Unassigned 17 Structure-agnostic E1 over packet [RFC4553] 18 Structure-agnostic T1 (DS1) over packet [RFC4553] 19 VPLS [RFC4761] 20 Structure-agnostic T3 (DS3) over packet [RFC4553] 21 Nx64kbit/s Basic Service using Structure-aware [RFC5086] 22-24 Unassigned 25 Frame Relay DLCI [RFC4619] 25-39 Unassigned 40 Structure-agnostic E3 over packet [RFC4553] 41 Octet-aligned payload for Structure-agnostic DS1 circuits [RFC4553] 42 E1 Nx64kbit/s with CAS using Structure-aware [RFC5086] 43 DS1 (ESF) Nx64kbit/s with CAS using Structure-aware [RFC5086] 44 DS1 (SF) Nx64kbit/s with CAS using Structure-aware [RFC5086] 45-127 Unassigned 128-251 Unassigned 252-255 Experimental Use [RFC6624] BGP Layer 2 TLV Types Reference [RFC6624] Available Formats [IMG] CSV Range Registration Procedures 0-127 Expert Review 128-251 First Come First Served 252-255 Experimental Use Value Description Reference 0 Reserved [RFC6624] 1 Circuit Status Vector [RFC6624] 2-127 Unassigned 128-251 Unassigned 252-255 Experimental Use [RFC6624] BGP AIGP Attribute Types Registration Procedure(s) Standards Action Reference [RFC7311] Available Formats [IMG] CSV Value Description Reference 0 Reserved [RFC7311] 1 AIGP [RFC7311] 2-255 Unassigned BGP Route Refresh Subcodes Reference [RFC7313] Available Formats [IMG] CSV Range Registration Procedures 0-127 Standards Action 128-254 First Come First Served Value Code Reference 0 Route-Refresh [RFC2918][RFC5291] 1 BoRR [RFC7313] 2 EoRR [RFC7313] 3-254 Unassigned 255 Reserved [RFC7313] P-Multicast Service Interface Tunnel (PMSI Tunnel) Tunnel Types Reference [RFC7385][RFC8317] Note The status of value 0xFF may only be changed through Standards Action [RFC8126]. Available Formats [IMG] CSV Range Registration Procedures 0x00-0x7A IETF Review 0x7B-0x7E Experimental Use 0x80-0xFA Composite Tunnel 0xFB-0xFE Experimental Use 0xFF Standards Action Value Meaning Reference 0x00 no tunnel information present [RFC6514] 0x01 RSVP-TE P2MP LSP [RFC6514] 0x02 mLDP P2MP LSP [RFC6514] 0x03 PIM-SSM Tree [RFC6514] 0x04 PIM-SM Tree [RFC6514] 0x05 BIDIR-PIM Tree [RFC6514] 0x06 Ingress Replication [RFC6514] 0x07 mLDP MP2MP LSP [RFC6514] 0x08 Transport Tunnel [RFC7524] 0x09 Unassigned 0x0A Assisted Replication Tunnel [RFC9574] 0x0B BIER [RFC8556] 0x0C SR-MPLS P2MP Tree (TEMPORARY - registered 2020-12-09, extension registered 2024-11-27, expires [draft-ietf-bess-mvpn-evpn-sr-p2mp-08] 2025-12-09) 0x0D-0x7A Unassigned 0x7B-0x7E Reserved for Experimental Use [RFC8317] 0x7F Reserved [RFC8317] 0x80-0xFA Reserved for Composite Tunnel [RFC8317] 0xFB-0xFE Reserved for Experimental Use [RFC7385] 0xFF wildcard transport tunnel type [RFC8338] P-Multicast Service Interface (PMSI) Tunnel Attribute Flags Registration Procedure(s) Standards Action Reference [RFC7902] Available Formats [IMG] CSV Value Name Reference 0 Unassigned 1 Extension [RFC7902] 2 Leaf Information Required per-Flow (LIR-pF) [RFC8534] 3-4 Assisted Replication Type (T) [RFC9574] 5 Broadcast and Multicast (BM) [RFC9574] 6 Unknown (U) [RFC9574] 7 Leaf Information Required (L) [RFC6514] BGP MCAST-VPN Route Types Registration Procedure(s) Standards Action Reference [RFC7441][RFC6514] Note Values may be assigned from one of several ranges: - Range 0x01-0x3f: Generic/PIM Range. Values are assigned from this range when the NLRI format associated with the route type presupposes that PIM or IGMP is the C-multicast control protocol, or when the NLRI format associated with the route type is independent of the C-multicast control protocol. - Range 0x43-0x7f: mLDP Range. Values are assigned from this range when the NLRI format associated with the route type presupposes that mLDP is the C-multicast control protocol. - Range 0x80-0xff: This range is reserved; values should not be assigned from this range. In general, whenever an assignment is requested from this registry, two codepoints should be requested at the same time: one from the Generic/PIM range (0x01-0x3f) and one from the mLDP range (0x43-0x7f). The two codepoints should have the same low-order 6 bits. If one of the two codepoints is not actually needed, it should be registered anyway, and marked as "Reserved." Available Formats [IMG] CSV Value Meaning Reference 0x00 Reserved [RFC7441][RFC6514] 0x01 Intra-AS I-PMSI A-D route [RFC7441][RFC6514] 0x02 Inter-AS I-PMSI A-D route [RFC7441][RFC6514] 0x03 S-PMSI A-D route [RFC7441][RFC6514] 0x04 Leaf A-D route [RFC7441][RFC6514] 0x05 Source Active A-D route [RFC7441][RFC6514] 0x06 Shared Tree Join route [RFC7441][RFC6514] 0x07 Source Tree Join route [RFC7441][RFC6514] 0x08-0x3f Unassigned (Generic/PIM range) 0x40-0x42 Reserved [RFC7441] 0x43 S-PMSI A-D route for C-multicast mLDP [RFC7441] 0x44 Leaf A-D route for C-multicast mLDP [RFC7441] 0x45-0x46 Reserved [RFC7441] 0x47 Source Tree Join route for C-multicast mLDP [RFC7441] 0x48-0x7f Unassigned (mLDP range) 0x80-0xff Reserved [RFC7441] BGP Prefix-SID TLV Types Registration Procedure(s) Expert Review Expert(s) Acee Lindem, Hannes Gredler Reference [RFC8669] Available Formats [IMG] CSV Value Type Reference 0 Reserved [RFC8669] 1 Label-Index [RFC8669] 2 Deprecated [RFC8669] 3 Originator SRGB [RFC8669] 4 Deprecated [RFC9252] 5 SRv6 L3 Service TLV [RFC9252] 6 SRv6 L2 Service TLV [RFC9252] 7-254 Unassigned 255 Reserved [RFC8669] BGP Prefix-SID Label-Index TLV Flags Registration Procedure(s) Expert Review Expert(s) Acee Lindem, Hannes Gredler Reference [RFC8669] Available Formats [IMG] CSV Value Name Reference 0x0001-0x8000 Unassigned BGP Prefix-SID Originator SRGB TLV Flags Registration Procedure(s) Expert Review Expert(s) Acee Lindem, Hannes Gredler Reference [RFC8669] Available Formats [IMG] CSV Value Name Reference 0x0001-0x8000 Unassigned BGP Graceful Restart Flags Registration Procedure(s) Standards Action Reference [RFC4724][RFC8538] Available Formats [IMG] CSV Bit Position Name Short Name Reference 0 Restart State R [RFC4724] 1 Notification N [RFC8538] 2-3 Unassigned BGP Graceful Restart Flags for Address Family Registration Procedure(s) Standards Action Reference [RFC4724][RFC8538] Available Formats [IMG] CSV Bit Position Name Short Name Reference 0 Forwarding State F [RFC4724] 1-7 Unassigned SFP Attribute TLVs Registration Procedure(s) First Come First Served Reference [RFC9015] Available Formats [IMG] CSV Type Name Reference Registration Date 0 Reserved [RFC9015] 1 Association TLV [RFC9015] 2020-09-02 2 Hop TLV [RFC9015] 2020-09-02 3 SFT TLV [RFC9015] 2020-09-02 4 MPLS Swapping/Stacking [RFC9015] 2020-09-02 5 SFP Traversal With MPLS [RFC9015] 2020-09-02 6-65534 Unassigned 65535 Reserved [RFC9015] SFP Association Type Registration Procedure(s) First Come First Served Reference [RFC9015] Available Formats [IMG] CSV Association Type Name Reference Registration Date 0 Reserved [RFC9015] 1 Bidirectional SFP [RFC9015] 2020-09-02 2-65534 Unassigned 65535 Reserved [RFC9015] SFC SPI/SI Representation Flags Registration Procedure(s) Standards Action Reference [RFC9015] Available Formats [IMG] CSV Value Name Reference 0 NSH data plane [RFC9015] 1 MPLS data plane [RFC9015] 2-15 Unassigned BFD Mode Reference [RFC9026] Available Formats [IMG] CSV Range Registration Procedures 0-175 IETF Review 176-249 First Come First Served 250-254 Experimental Use 255 IETF Review Value Description Reference 0 Reserved [RFC9026] 1 P2MP BFD Session [RFC9026] 2-175 Unassigned 176 S-BFD for SRv6 Locator Session [draft-wang-bess-sbfd-discriminator-04] 177 S-BFD for Common Session [draft-wang-bess-sbfd-discriminator-04] 178-249 Unassigned 250-254 Experimental Use [RFC9026] 255 Reserved [RFC9026] BFD Discriminator Optional TLV Type Reference [RFC9026] Available Formats [IMG] CSV Range Registration Procedures 0-175 IETF Review 176-249 First Come First Served 250-254 Experimental Use 255 IETF Review Value Description Reference 0 Reserved [RFC9026] 1 Source IP Address [RFC9026] 2-175 Unassigned 176-249 Unassigned 250-254 Experimental Use [RFC9026] 255 Reserved [RFC9026] SRv6 Service Sub-TLV Types Reference [RFC9252] Available Formats [IMG] CSV Range Registration Procedures 0-127 IETF Review 128-254 First Come First Served 255 IETF Review Value Type Reference 0 Reserved [RFC9252] 1 SRv6 SID Information Sub-TLV [RFC9252] 2-254 Unassigned 255 Reserved [RFC9252] SRv6 Service Data Sub-Sub-TLV Types Reference [RFC9252] Available Formats [IMG] CSV Range Registration Procedures 0-127 IETF Review 128-254 First Come First Served 255 IETF Review Value Type Reference 0 Reserved [RFC9252] 1 SRv6 SID Structure Sub-Sub-TLV [RFC9252] 2-254 Unassigned 255 Reserved [RFC9252] BGP SRv6 Service SID Flags Registration Procedure(s) IETF Review Reference [RFC9252] Available Formats [IMG] CSV Bit Position Name Reference 0-7 Unassigned Long-Lived Graceful Restart Flags for Address Family Registration Procedure(s) Standards Action Reference [RFC9494] Available Formats [IMG] CSV Bit Position Name Short Name Reference 0 Preservation of state F [RFC9494] 1-7 Unassigned BGP BIER TLV and Sub-TLV Types Registration Procedure(s) First Come First Served Reference [RFC9793] Available Formats [IMG] CSV Value Name Reference 0 Reserved [RFC9793] 1 BIER TLV [RFC9793] 2 MPLS Encapsulation sub-TLV [RFC9793] 3 non-MPLS Encapsulation sub-TLV [RFC9793] 4 BIER Nexthop sub-TLV [RFC9793] 5 BIER PHP Request [RFC-ietf-bier-php-16] 6-65535 Unassigned BGP CAR NLRI Types Registration Procedure(s) Specification Required Expert(s) Unassigned Reference [RFC-ietf-idr-bgp-car-16] Available Formats [IMG] CSV Type NLRI Type Reference 0 Reserved [RFC-ietf-idr-bgp-car-16] 1 Color-Aware Route [RFC-ietf-idr-bgp-car-16] 2 IP Prefix [RFC-ietf-idr-bgp-car-16] 3-255 Unassigned BGP CAR NLRI TLV Types Registration Procedure(s) Specification Required Expert(s) Unassigned Reference [RFC-ietf-idr-bgp-car-16] Available Formats [IMG] CSV Type NLRI TLV Type Reference 0 Reserved [RFC-ietf-idr-bgp-car-16] 1 Label [RFC-ietf-idr-bgp-car-16] 2 Label Index [RFC-ietf-idr-bgp-car-16] 3 SRv6 SID [RFC-ietf-idr-bgp-car-16] 4-64 Unassigned Contact Information ID Name Contact URI Last Updated [Eric_Rosen] Eric Rosen mailto:erosen&cisco.com 2010-02-23 [Gargi_Nalawade] Gargi Nalawade mailto:gargi&cisco.com 2004-02 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