Rayhaan JaufeerallyandClaude Opus 5.5
72444c2706
Control communities could say which peers a route goes to, by AS. Now
they can also name sessions by group, and ask for prepends:
L:11:P .. L:13:P our AS once to three times more towards AS P
(P 0: towards every peer in another AS)
L:20:G / L:21:G not to / only to the sessions of group G
L:31:G .. L:33:G our AS once to three times more towards group G
A group is a number given to sessions in the configuration (`groups` of
a peer): those at one exchange, or those over one link. The same network
at two exchanges is one AS but two sessions, which is what steering
inbound traffic between exchanges needs. Of several prepends that apply
the most counts, on top of the session's own as_path_prepend. Functions
2 to 9, as the documentation already promised, and 100 and up stay
informational; 10 to 99 are kept for actions to come.
They are acted on where a route leaves our AS, and taken off there; our
informational communities are not. To a peer in our own AS a route goes
with them, unchanged, so that a mark put on at one router is acted on at
another. Before, they were acted on and taken off on internal sessions
too, so a route marked "to nobody" did not even reach our own routers.
And they are ours to give: the communities of our own AS (L:n, L:n:m,
and 0:n where control communities are on) are taken off every route
from a peer in another AS as it comes in, before import marks are put
on. A peer at an exchange could otherwise decide where its routes go
from us, and set our informational marks. A customer that is to steer
its own routes is given import.accept_control_communities. An UPDATE
without any of ours is still taken as it came, without being written
out again.
This changes what a customer that set control communities gets: it now
needs accept_control_communities. The transit example and the interop
lab say so; the lab also has FRR, as a customer, ask for a prepend
towards BIRD's group, and BIRD, as a provider, have its "not to" taken
off.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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
- Overview and quick start
- User guide: BGP neighbors, import policy, BGP roles, RPKI, kernel route installation, route advertisement, configuration examples
- Deployment and monitoring
- Reference: configuration, HTTP API, metrics, supported standards
- Architecture and testing
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.