# Supported standards

> The RFCs ansage implements, and what it deliberately leaves out.

## BGP

| RFC                                                                                            | What                                              | In ansage                                                                                                                |
| ---------------------------------------------------------------------------------------------- | ------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |
| [4271](https://www.rfc-editor.org/rfc/rfc4271)                                                 | BGP-4                                             | sessions, state machine, best path selection                                                                             |
| [4760](https://www.rfc-editor.org/rfc/rfc4760)                                                 | Multiprotocol extensions                          | IPv4 and IPv6 unicast on one session                                                                                     |
| [2545](https://www.rfc-editor.org/rfc/rfc2545)                                                 | BGP for IPv6                                      | global and link-local next hops                                                                                          |
| [5492](https://www.rfc-editor.org/rfc/rfc5492)                                                 | Capabilities advertisement                        |                                                                                                                          |
| [6793](https://www.rfc-editor.org/rfc/rfc6793)                                                 | 4-octet AS numbers                                |                                                                                                                          |
| [8654](https://www.rfc-editor.org/rfc/rfc8654)                                                 | Extended messages                                 | UPDATEs up to 65535 bytes                                                                                                |
| [9072](https://www.rfc-editor.org/rfc/rfc9072)                                                 | Extended optional parameters length               | decoding OPENs that use it                                                                                               |
| [2918](https://www.rfc-editor.org/rfc/rfc2918)                                                 | Route refresh                                     | answers a refresh with our routes; asks for one when an import policy changes                                            |
| [4724](https://www.rfc-editor.org/rfc/rfc4724)                                                 | Graceful Restart                                  | `graceful_restart`, `ansage upgrade`                                                                                     |
| [8538](https://www.rfc-editor.org/rfc/rfc8538)                                                 | Notification support for Graceful Restart (N bit) | Hard Reset on stop                                                                                                       |
| [8326](https://www.rfc-editor.org/rfc/rfc8326)                                                 | Graceful shutdown                                 | `ansage drain`, `drain_time`                                                                                             |
| [8212](https://www.rfc-editor.org/rfc/rfc8212)                                                 | Default eBGP route propagation behavior           | `import = "none"` by default                                                                                             |
| [9234](https://www.rfc-editor.org/rfc/rfc9234)                                                 | Route leak prevention with roles                  | `role`, `strict_role`: BGP Role capability, Only-To-Customer attribute, no provider or peer routes to providers or peers |
| [7606](https://www.rfc-editor.org/rfc/rfc7606)                                                 | Revised error handling for UPDATEs                | treat-as-withdraw, attribute discard                                                                                     |
| [4486](https://www.rfc-editor.org/rfc/rfc4486)                                                 | Cease subcodes                                    | max prefixes, reconnect backoff                                                                                          |
| [9003](https://www.rfc-editor.org/rfc/rfc9003)                                                 | Shutdown communication                            | `ansage peer N disable --reason`                                                                                         |
| [6286](https://www.rfc-editor.org/rfc/rfc6286)                                                 | AS-wide unique BGP identifier                     |                                                                                                                          |
| [6608](https://www.rfc-editor.org/rfc/rfc6608)                                                 | Subcodes for BGP FSM errors                       |                                                                                                                          |
| [1997](https://www.rfc-editor.org/rfc/rfc1997), [8092](https://www.rfc-editor.org/rfc/rfc8092) | Communities, large communities                    | shown in `ansage show rib`, matched and set by filters; NO_EXPORT and NO_ADVERTISE are honored                           |

## Transport and security

| RFC                                            | What    | In ansage                   |
| ---------------------------------------------- | ------- | --------------------------- |
| [2385](https://www.rfc-editor.org/rfc/rfc2385) | TCP-MD5 | `password`, `password_file` |
| [5082](https://www.rfc-editor.org/rfc/rfc5082) | GTSM    | `ttl_security`              |

## Not supported

- Address families other than IPv4 and IPv6 unicast (no VPN, EVPN, flowspec, multicast).
- Route reflection, route servers (`role = "rs-client"`), confederations.
- Enhanced route refresh (RFC 7313), outbound route filtering (ORF, RFC 5291), ADD-PATH, BFD, TCP-AO.
- With `[kernel]`: routes whose next hop is of the other family (RFC 8950) are not installed.

The protocol code is the `ansage-bgp` crate, see [Crates](/docs/development/crates.md).