Rayhaan JaufeerallyandClaude Opus 5.5 65f136048e Graceful restart (RFC 4724, RFC 8538)
A peer that restarts keeps its routes with us, and we keep ours with our
peers while we restart, so that a restart withdraws nothing across the
network and the machine goes on forwarding. On by default for every
peer; `graceful_restart` sets the restart time we give, caps how long a
peer's routes are kept, or turns it off.

When a peer restarts: its routes are marked stale in the routing table,
and chosen as before, for at most its restart time. When it is back, what
it sends again is fresh, and the stale routes of a family go at its
End-of-RIB marker, or after the cap; at once for a family whose
forwarding it did not keep. Only a connection that failed counts as a
restart, and, with RFC 8538 agreed, an expired hold timer or a
NOTIFICATION other than a Hard Reset. The stale mark is a bit of the
route's word that selection never looks at.

When we restart: SIGUSR1 leaves the kernel's routes where they are,
closes the sessions without a word where graceful restart is agreed, and
exits with status 75, on which the systemd unit starts us again. The next
start finds the routes in the kernel, says so in its OPENs (R, and F where
forwarding was kept), and has them go once every peer has sent its
End-of-RIB. Our own End-of-RIB markers for learned routes wait for that
too. SIGTERM still stops for good, now with a Hard Reset where RFC 8538 is
agreed, as are errors of ours.

The status page and API show what was agreed with each peer, the routes
kept while a peer restarts, and which routes are stale. Tested against
FRR and BIRD in a new phase of the interoperability lab, and with routes
kept in a real kernel over a restart.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-04 22:43:47 +02:00
2026-10-02 22:47:57 +02:00
2026-10-02 22:47:57 +02:00

Ferrix BGP

An implementation of the Border Gateway Protocol, which is used to exchange routing and control plane information between Autonomous Systems.

The aim of this project is to provide a modern, high performance, secure, programmatic and customizable software package that can be useful to network operators, researchers, and people interested in Internet.

Current status

The daemon establishes BGP sessions with configured neighbors, evaluates received routes against import policy, validates them with the RPKI (route origin validation and ASPA), selects the best path for each prefix, and, on Linux, installs it in the kernel. It advertises the routes that it originates and, to neighbors configured for it, the best paths learned from other neighbors, as BGP roles (RFC 9234) and communities permit.

Ferrix has not been deployed in a production network.

Unsupported Features

  • Route reflection, per-client best path selection for route servers, and ADD-PATH for advertised routes
  • TCP-AO, TCP MD5, and GTSM
  • Graceful restart, BFD, and configuration changes without a restart
  • Recursive resolution of next hops that are not directly connected

Layout

Crate What is in it
crates/primitives Prefixes, address families, parsing helpers
crates/packet The wire format: messages, attributes, capabilities
crates/rib The routing table, best route selection, the journal of changes
crates/rpki The RTR client; origin validation and ASPA path verification
crates/fib The best routes in the Linux kernel, over netlink
crates/server Sessions, the state machine, policy, configuration
crates/web The status page, HTTP API and metrics
bin/bgp The daemon

Documentation

The documentation is a website built from docs/ with Zola:

zola --root docs serve     # http://127.0.0.1:1111

Development

CI runs these on every push, and fails on any warning:

cargo fmt --all -- --check
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace
RUSTDOCFLAGS="-D warnings" cargo doc --workspace --no-deps --document-private-items
zola --root docs build

It also runs the tests that need a real Linux kernel (scripts/kernel-tests.sh) and the lab with FRR, BIRD and Routinator (scripts/interop/lab.sh); scripts/linux-vm.sh runs either from macOS.

Lints are configured once, under [workspace.lints] in the root Cargo.toml. unsafe code is forbidden throughout.

cargo test includes property tests: generated messages must survive being written and read back, and no input, however damaged, may make a parser panic. They take about a second; for a longer hunt:

PROPTEST_CASES=1000000 cargo test --release -p bgp-packet --test properties

Coverage-guided fuzz targets for the same parsers are in fuzz/; see fuzz/README.md. CI runs each of them for a minute.

License

Apache License 2.0; see LICENSE.

S
Description
Ferrix BGP Speaker
Readme
5 MiB
0 Stars 0 Watchers 0 Forks
Languages
Rust 92.3%
Shell 4.2%
HTML 3.5%