rayhaan/ferrix
0
0 Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
630c1759186c15d25ac4862035a1e4058e8158e2
ferrix/docs/RFCs.md
T
Rayhaan JaufeerallyandClaude Fable 5.1 630c175918 Rework the speaker: sans-I/O FSM, sharded table, RFC 7606, ADD-PATH 
The work of the speaker-cleanup branch as one commit; the branch keeps
the step-by-step history.

Sessions
- The state machine is a pure function from events to actions, driven by
  one task per connection. Idle, Connect and Active belong to a dialer
  that keeps configured peers up with backoff.
- Capabilities are negotiated: address families, four-octet AS numbers
  with AS_TRANS and AS4_PATH, route refresh, ADD-PATH per family and
  direction.
- Collision detection per RFC 4271 section 6.8, by address and
  identifier.
- Connections are taken only from configured peers, a few per address.
- A panic in a session is contained and answered with a Cease; a core
  task that stops shuts the server down with a Cease to every peer.
- Writes that make no progress are given up (RFC 9687).

Codec
- Malformed UPDATEs are handled as RFC 7606 says: treat-as-withdraw,
  attribute discard, or session reset, with the NOTIFICATION to send.
- Address families are open types; any can be named and ignored.
- Prefixes are fixed-size values, normalised, with path identifiers.
- Lengths are filled in after writing; one definition of each type code.
- Property tests and fuzz targets for every decoder.

Routing table
- Adj-RIBs-In and Loc-RIB in one sharded table that sessions write to
  directly. Routes are sixteen bytes; attribute sets are interned in
  wire form. Best-path selection per RFC 4271 section 9.1.2.2 with
  deterministic MED.
- A journal per shard lets followers read changes at their own pace;
  one that falls behind is resynchronised.
- On a RIPE RIS dump of 148 peers and 39.3M routes: loaded in 2.0 s on
  12 cores, about 52 bytes a route.

Announcing
- Originated routes come from the configuration. Each session has its
  own exporter with an Adj-RIB-Out, so a slow peer delays only itself.
- Routes to a peer in our own AS have an empty path and a LOCAL_PREF.

Operations
- HTTP status page, JSON API, event stream and Prometheus metrics.
- Benchmarks on synthetic and real tables.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 12:35:54 +02:00

175 lines
5.7 KiB
Markdown
Raw Blame History

# RFCs
Tracks which RFCs are implemented, partially implemented, or only represented
in the wire format layer.
**Legend**
- ✅ Implemented — functional end-to-end
- 🟡 Wire format only — parsed and serialised correctly, but not yet acted on
- ❌ Not implemented
---
## Core BGP
### RFC 4271 — A Border Gateway Protocol 4 (BGP-4)
https://datatracker.ietf.org/doc/html/rfc4271
The base protocol specification.
| Section | Description | Status |
|---------|-------------|--------|
| §4.1 | Message framing (marker, length, type) | ✅ |
| §4.2 | OPEN message | ✅ |
| §4.3 | UPDATE message (path attributes, NLRI, withdrawn routes) | ✅ |
| §4.4 | KEEPALIVE message | ✅ |
| §4.5 | NOTIFICATION message (all error codes and subcodes) | ✅ |
| §8 | FSM — passive (inbound) side: OpenSent → OpenConfirm → Established | ✅ |
| §8 | FSM — active (outbound) side: dial configured peers, exponential retry | ✅ |
| §6.2 | Bad Peer AS check against configured ASN | ✅ |
| §6.7 / RFC 4486 | Cease / Administrative Shutdown sent to every peer on SIGINT or SIGTERM | ✅ |
| §6.8 | Connection collision detection (BGP Identifier comparison, Cease / Connection Collision Resolution) | ✅ |
| §8.1.1 | Optional `CollisionDetectEstablishedState` (`collision_detect_established_state`) | ✅ |
| §6.2 | Bad BGP Identifier check (peer using our identifier, or 0.0.0.0) | ✅ |
| §9 | Decision process / best-path selection | ❌ |
| §9 | Adj-RIB-In (per-peer table of received routes) | ✅ |
| §9 | Locally originated routes, advertised to all established peers | ✅ |
| §9 | Loc-RIB / Adj-RIB-Out for routes learned from peers (re-advertisement) | ❌ |
| §9.2 | Hold timer reset on any received message (not only KEEPALIVE) | ✅ |
---
## Capability and Session Extensions
### RFC 6793 — BGP Support for Four-Octet Autonomous System (AS) Number Space
https://datatracker.ietf.org/doc/html/rfc6793
| Feature | Status |
|---------|--------|
| `AS_TRANS` (23456) sentinel | ✅ |
| `FourByteAsn` capability advertisement and parsing | ✅ |
| 4-byte AS_PATH segment encoding/decoding via `ParserContext` | ✅ |
| 4-byte ASN negotiation in FSM | ✅ |
### RFC 9072 — Extended Optional Parameters Length for BGP OPEN Message
https://datatracker.ietf.org/doc/html/rfc9072
| Feature | Status |
|---------|--------|
| Parsing extended-length OPEN (0xFF sentinel) | ✅ |
| Serialising extended-length OPEN when options exceed 255 bytes | ✅ |
### RFC 2918 — Route Refresh Capability for BGP-4
https://datatracker.ietf.org/doc/html/rfc2918
| Feature | Status |
|---------|--------|
| `RouteRefresh` capability advertisement | ✅ |
| `ROUTE-REFRESH` message type (5) framing | ✅ |
| AFI/SAFI payload parsing | ❌ |
| Acting on received ROUTE-REFRESH (re-advertising all local routes, regardless of the AFI/SAFI asked for) | ✅ |
### RFC 7313 — Enhanced Route Refresh Capability for BGP-4
https://datatracker.ietf.org/doc/html/rfc7313
| Feature | Status |
|---------|--------|
| `EnhancedRouteRefresh` capability wire format | 🟡 |
### RFC 4724 — Graceful Restart Mechanism for BGP
https://datatracker.ietf.org/doc/html/rfc4724
| Feature | Status |
|---------|--------|
| `GracefulRestart` capability wire format | 🟡 |
| Restart state and forwarding preserved across sessions | ❌ |
### RFC 9494 — Long-Lived Graceful Restart for BGP
https://datatracker.ietf.org/doc/html/rfc9494
| Feature | Status |
|---------|--------|
| `LongLivedGracefulRestart` capability wire format | 🟡 |
### RFC 8654 — Extended Message Support for BGP
https://datatracker.ietf.org/doc/html/rfc8654
| Feature | Status |
|---------|--------|
| `ExtendedMessage` capability wire format | 🟡 |
| Raising `BGP_MAX_MSG_LEN` to 65535 when negotiated | ❌ |
---
## Multiprotocol and NLRI
### RFC 2858 — Multiprotocol Extensions for BGP-4
https://datatracker.ietf.org/doc/html/rfc2858
| Feature | Status |
|---------|--------|
| `MultiProtocol` capability advertisement (IPv4 and IPv6 unicast) | ✅ |
| `MP_REACH_NLRI` path attribute (parse, serialise) | ✅ |
| `MP_UNREACH_NLRI` path attribute (parse, serialise) | ✅ |
| IPv4 and IPv6 next-hop encoding | ✅ |
### RFC 8950 — Advertising IPv4 Network Layer Reachability Information (NLRI) with an IPv6 Next Hop
https://datatracker.ietf.org/doc/html/rfc8950
| Feature | Status |
|---------|--------|
| `ExtendedNextHop` capability wire format | 🟡 |
---
## Path Attributes and Communities
### RFC 1997 — BGP Communities Attribute
https://datatracker.ietf.org/doc/html/rfc1997
| Feature | Status |
|---------|--------|
| `COMMUNITIES` path attribute (parse, serialise) | ✅ |
| Attach to locally originated routes | ✅ |
### RFC 4360 — BGP Extended Communities Attribute
https://datatracker.ietf.org/doc/html/rfc4360
| Feature | Status |
|---------|--------|
| `EXTENDED_COMMUNITIES` path attribute (parse, serialise) | ✅ |
| AS-specific, IPv4-address-specific, opaque, route-target, route-origin subtypes | ✅ |
### RFC 8092 — BGP Large Communities Attribute
https://datatracker.ietf.org/doc/html/rfc8092
| Feature | Status |
|---------|--------|
| `LARGE_COMMUNITIES` path attribute (parse, serialise) | ✅ |
| Attach to locally originated routes | ✅ |
---
## Other Capabilities (Wire Format Only)
The following capabilities are parsed and serialised correctly but have no
functional behaviour implemented beyond that.
| RFC | Capability | Status |
|-----|-----------|--------|
| RFC 5291 | Outbound Route Filtering (ORF) | 🟡 |
| RFC 7911 | ADD-PATH | 🟡 |
| RFC 8205 | BGPsec | 🟡 |
---
## Error Handling
### RFC 9687 — BGP Send Hold Timer
https://datatracker.ietf.org/doc/html/rfc9687
| Feature | Status |
|---------|--------|
| `SendHoldTimer` error code (8) defined | ✅ |
| Send hold timer enforcement | ❌ |
Reference in new issue View Git Blame Copy Permalink