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ferrix/testdata/server.textpb
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Rayhaan JaufeerallyandClaude Fable 5.1 1fc44798b7 Install best routes in the Linux kernel over netlink
New crate bgp-fib. It follows the routing table's best routes and keeps
the kernel's routing table the same, and learns the machine's interfaces
and addresses from the kernel, which is what says whether a next hop can
be reached.

- netlink: the rtnetlink messages used (routes, addresses, links, errors),
  as bytes and back. No I/O; property tested and fuzzed.
- interfaces: what is directly reachable, and from which interface.
- plan: what to ask the kernel for, given the best routes and what the
  kernel has. No I/O; tested against a model kernel.
- kernel (Linux only): the sockets and the task. Requests go in batches;
  routes of ours found at startup are kept if still right and removed if
  not; a change of interfaces has every route worked out again; a clean
  stop removes our routes.

Only routes marked proto bgp with the configured table and metric are
ever touched. A best route is installed if its next hop is a neighbor;
next hops further away are not resolved through other routes yet, and
such prefixes are counted and shown instead.

Configured with `kernel { table metric }`; off by default. The daemon
needs CAP_NET_ADMIN and stops if the kernel refuses it. On shutdown it
closes sessions and then removes its routes.

/api/kernel and the status page show installed, unresolved and refused
counts, the last error and the interfaces; five bgp_kernel_* metrics.

Testing: scripts/kernel-tests.sh runs, in network namespaces of their
own and with only the capabilities the daemon needs, the installer
against `ip route`, the daemon with a peer, and two daemons that route
for each other with pings across over IPv4 and IPv6.
scripts/linux-vm.sh runs that, or anything else, in a Lima VM from
macOS. CI runs the kernel tests and fuzzes the netlink decoder.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-02 15:15:43 +02:00

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# A worked example; the fields are documented in
# crates/server/proto/config.proto.
router_id: "10.0.0.1"
local_asn: 65000
# Where to accept BGP connections. Port 179 needs privileges; pick another
# port to run unprivileged against a peer that dials a custom port.
listen_endpoints { address: "127.0.0.1" port: 179 }
listen_endpoints { address: "::1" port: 179 }
# A peer we connect to and accept connections from. Connections from any
# other address are closed unread, unless accept_unconfigured_peers is set,
# which is for a closed test network only.
peers {
name: "r1"
endpoint { address: "127.0.0.1" port: 1791 }
remote_asn: 65001
hold_time_seconds: 30
# Offer only these families to the peer. Left out, all are offered.
address_families: IPV4_UNICAST
address_families: IPV6_UNICAST
# Take several routes for a prefix from this peer, if it offers to send
# them (ADD-PATH). Also ADD_PATH_SEND and ADD_PATH_BOTH. Off by default.
add_path: ADD_PATH_RECEIVE
# What the peer is to us: PROVIDER, CUSTOMER, PEER, ROUTE_SERVER or
# ROUTE_SERVER_CLIENT. With it the peer must not claim to be something
# else (RFC 9234), routes are marked "only to customer" and leaks of
# marked routes are refused; and with a validator that has ASPAs, the
# AS paths of the peer's routes are verified.
# role: PEER
# Refuse the peer if its OPEN does not say what it is.
# require_role: true
# Which of the peer's routes are taken. Without this block the general
# checks still apply: no private or reserved prefixes or AS numbers,
# nothing longer than /24 or /48, no default route, and a path that
# begins with the peer's AS. This example is a test network that uses
# exactly such prefixes and AS numbers, so it takes them.
import {
# More routes than this ends the session and keeps the peer down
# for hold_down_seconds (600 unless set).
max_prefixes: 1000
accept_bogons: true
# For a real peer: the prefixes and origin ASes it may announce,
# as generated from the routing registries.
# prefixes { prefix: "193.0.0.0/21" max_length: 24 }
# origin_asns: 3333
}
}
connect_retry_seconds: 5
# Let a restarted peer replace a stale Established session immediately
# (RFC 4271 CollisionDetectEstablishedState). Default false.
collision_detect_established_state: false
# Routes this router originates, announced to every peer.
originate { prefix: "10.100.0.0/16" }
originate {
prefix: "2001:db8:100::/48"
med: 50
communities: "65000:100"
large_communities: "65000:1:2"
}
# Validation with the RPKI: refuse routes whose origin AS is not the one the
# holder of the addresses authorised, and, from peers with a role, routes
# whose AS path is a leak. Point it at a validator's RTR server.
# rpki { caches { address: "127.0.0.1" port: 3323 } }
# Put the best route of every prefix in the kernel's routing table, so that
# this machine forwards by them (Linux; needs CAP_NET_ADMIN). Routes are
# marked "proto bgp"; table and metric default to 254 (main) and 20.
# kernel {}
# Read-only status page, JSON API and metrics. It has no authentication:
# keep it on loopback or behind a reverse proxy.
http_endpoint { address: "127.0.0.1" port: 8080 }