References: RFC 4271
| Value | Defined by | Name | Description | References |
|---|---|---|---|---|
| 0 | IANA | Reserved | - | - |
| 1 | IANA | ORIGIN | - | RFC 4271 |
| 2 | IANA | AS_PATH | - | RFC 4271 |
| 3 | IANA | NEXT_HOP | - | RFC 4271 |
| 4 | IANA | MULTI_EXIT_DISC | - | RFC 4271 |
| 5 | IANA | LOCAL_PREF | - | RFC 4271 |
| 6 | IANA | ATOMIC_AGGREGATE | - | RFC 4271 |
| 7 | IANA | AGGREGATOR | - | RFC 4271 |
| 8 | IANA | COMMUNITY | - | RFC 1997 |
| 9 | IANA | ORIGINATOR_ID | - | RFC 4456 |
| 10 | IANA | CLUSTER_LIST | - | RFC 4456 |
| 11 | IANA | DPA (deprecated) | - | RFC 6938, Chen, E., Bates, T., "Destination Preference Attribute for BGP", Work in progress, March 1996. |
| 12 | IANA | ADVERTISER (historic) (deprecated) | - | RFC 1863, RFC 4223, RFC 6938 |
| 13 | IANA | RCID_PATH / CLUSTER_ID (Historic) (deprecated) | - | RFC 1863, RFC 4223, RFC 6938 |
| 14 | IANA | MP_REACH_NLRI | - | RFC 4760 |
| 15 | IANA | MP_UNREACH_NLRI | - | RFC 4760 |
| 16 | IANA | EXTENDED COMMUNITIES | - | Eric Rosen, RFC 4360 |
| 17 | IANA | AS4_PATH | - | RFC 6793 |
| 18 | IANA | AS4_AGGREGATOR | - | RFC 6793 |
| 19 | IANA | SAFI Specific Attribute (SSA) (deprecated) | - | Gargi Nalawade |
| 20 | IANA | Connector Attribute (deprecated) | - | RFC 6037 |
| 21 | IANA | AS_PATHLIMIT (deprecated) | - | - |
| 22 | IANA | PMSI_TUNNEL | - | RFC 6514 |
| 23 | IANA | Tunnel Encapsulation | - | RFC 9012 |
| 24 | IANA | Traffic Engineering | - | RFC 5543 |
| 25 | IANA | IPv6 Address Specific Extended Community | - | RFC 5701 |
| 26 | IANA | AIGP | - | RFC 7311 |
| 27 | IANA | PE Distinguisher Labels | - | RFC 6514 |
| 28 | IANA | BGP Entropy Label Capability Attribute (deprecated) | - | RFC 6790, RFC 7447 |
| 29 | IANA | BGP-LS Attribute | - | RFC 7752 |
| 30 | IANA | Deprecated | - | RFC 8093 |
| 31 | IANA | Deprecated | - | RFC 8093 |
| 32 | IANA | LARGE_COMMUNITY | - | RFC 8092 |
| 33 | IANA | BGPsec_Path | - | RFC 8205 |
| 34 | IANA | BGP Community Container Attribute (TEMPORARY - registered 2017-07-28, extension registered 2018-08-10, expires 2019-07-28) | - | - |
| 35 | IANA | Only to Customer (OTC) | - | RFC 9234 |
| 36 | IANA | BGP Domain Path (D-PATH) (TEMPORARY - registered 2019-07-08, extension registered 2022-05-13, expires 2023-07-08) | - | - |
| 37 | IANA | SFP attribute | - | RFC 9015 |
| 38 | IANA | BFD Discriminator | - | RFC 9026 |
| 39 | IANA | BGP Router Capabilities (RCA) (TEMPORARY - registered 2022-12-20, expires 2023-12-20) | - | - |
| 40 | IANA | BGP Prefix-SID | - | RFC 8669 |
| 128 | IANA | ATTR_SET | - | RFC 6368 |
| 129 | IANA | Deprecated | - | RFC 8093 |
| 241 | IANA | Deprecated | - | RFC 8093 |
| 242 | IANA | Deprecated | - | RFC 8093 |
| 243 | IANA | Deprecated | - | RFC 8093 |
| 255 | IANA | Reserved for development | - | RFC 2042 |