comparison.md

BGP Implementation Comparison

A feature comparison of open-source BGP daemon implementations.

Disclaimer: This comparison was generated with AI assistance (partially based on rustbgpd's comparison) and is provided for informational purposes only. All listed projects are under active development and their capabilities change over time. Verify current features against each project's own documentation before making decisions. Corrections and updates are welcome via the issue tracker.

Last updated: 2026-03-25

Overview

	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
Language	Go	Rust	C	Go	Rust	C	Go	Python	C	C	Java
License	AGPL-3.0	MIT	GPL-2.0+	Apache-2.0	Apache-2.0	GPL-2.0	Apache-2.0	BSD-3-Clause	ISC	GPL-2.0+	Free
Primary interface	CLI (ze) + SSH	gRPC	CLI (birdc)	gRPC	gRPC	CLI (vtysh)	gRPC	CLI + API	CLI (bgpctl)	CLI (birdc)	CLI (telnet/SSH)
First release	2026	2026	2024	2018	2019	2017	2014	2010	2004	1998	2012
Maturity	Pre-release	Pre-release	Production	Niche	Experimental	Production	Production	Production	Production	Production	Production
Multithreaded	Yes (goroutines)	Yes (tokio)	Yes	Yes (goroutines)	Yes (multi-core)	No	Yes (goroutines)	No	Yes (3-process)	No	Yes (per-peer)
Plugin architecture	Yes	No	No	No	No	No	No	No	No	No	No
YANG-modeled config	Yes	No	No	No	No	Partial	No	No	No	No	No

Address Families

AFI/SAFI	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
IPv4 Unicast	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
IPv6 Unicast	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
IPv4 Multicast	Yes	No	Yes	No	No	Yes	Yes	No	No	Yes	Yes
IPv6 Multicast	Yes	No	Yes	No	No	Yes	Yes	No	No	Yes	Yes
IPv4 Labeled Unicast	Yes	No	No	No	No	Yes	Yes	Yes	No	No	Yes
IPv6 Labeled Unicast	Yes	No	No	No	No	Yes	Yes	Yes	No	No	Yes
VPNv4 (RFC 4364)	Yes	No	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
VPNv6	Yes	No	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
L2VPN EVPN (RFC 7432)	Yes	No	Yes	No	No	Yes	Yes	Yes	No	Yes	Yes
L2VPN VPLS	Yes	No	No	No	No	No	Yes	Yes	No	No	Yes
IPv4 FlowSpec (RFC 8955)	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
IPv6 FlowSpec	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
VPN FlowSpec	Yes	No	No	No	No	No	Yes	No	No	No	Yes
BGP-LS (RFC 7752)	Decode (40 TLVs)	No	No	No	No	No	Yes	Decode	No	No	Yes
SR Policy	No	No	No	No	No	No	Yes	No	No	No	Partial
IPv4/IPv6 MUP	Yes	No	No	No	No	No	No	No	No	No	Yes
IPv4/IPv6 MVPN	Decode	No	No	No	No	No	No	No	No	No	Yes
IPv4 RTC (RFC 4684)	Decode	No	No	No	No	No	No	Yes	No	No	Yes

Core Protocol

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
RFC 4271 FSM	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
4-byte ASN (RFC 6793)	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Capability negotiation	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Route Refresh (RFC 2918)	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
Enhanced Route Refresh (RFC 7313)	Yes	Yes	Yes	No	No	Yes	No	Yes	Yes	Yes	Yes
Graceful Restart (RFC 4724)	Yes	Yes	Yes	No	No	Yes	Yes	Partial	Yes	Yes	Yes
Long-Lived GR (RFC 9494)	Yes	Yes	Yes	No	No	Partial	Yes	No	No	Yes	Yes
Notification GR (RFC 8538)	Yes	Yes	No	No	No	No	Yes	No	Yes	No	No
Add-Path (RFC 7911)	Yes	Yes	Yes	Yes	Rx only	Yes	Yes	Yes	Yes	Yes	Yes
Extended Messages (RFC 8654)	Yes	Yes	Yes	No	No	Yes	No	Yes	Yes	Yes	Yes
Extended Nexthop (RFC 8950)	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
Route Reflector (RFC 4456)	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	Yes	Yes
Confederation (RFC 5065)	No	No	Yes	No	No	Yes	Yes	No	No	Yes	Yes
Admin Shutdown (RFC 8203)	Yes	Yes	Yes	Partial	No	Yes	Yes	Yes	Yes	Yes	Partial
BGP Roles (RFC 9234)	Yes	No	Yes	Yes	No	No	No	No	Yes	Yes	Partial
Prefix Limit (RFC 4486)	Yes	Yes	Yes	No	No	Yes	Yes	No	Yes	Yes	Yes

Policy & Route Manipulation

Ze takes a programmable approach to policy: external plugin filters manipulate routes via the redistribution {} config block using <plugin>:<filter> references. Filters chain as piped transforms (accept/reject/modify) with delta-only output. RFC-mandated checks run as default filters that can be selectively overridden.

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
Prefix matching (ge/le)	No	Yes	Yes	Yes	Partial	Yes	Yes	No	Yes	Yes	Yes
AS-path regex	No	Yes	Yes	No	No	Yes	Yes	No	Yes	Yes	Yes
Standard communities	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Extended communities	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes
Large communities (RFC 8092)	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes
Community add/remove/replace	API	Yes	Yes	Yes	No	Yes	Yes	API	Yes	Yes	Yes
MED manipulation	API	Yes	Yes	Yes	No	Yes	Yes	API	Yes	Yes	Yes
LOCAL_PREF set	API	Yes	Yes	Yes	No	Yes	Yes	API	Yes	Yes	Yes
AS-path prepend	API	Yes	Yes	Yes	No	Yes	Yes	API	Yes	Yes	Yes
Next-hop set/self	API	Yes	Yes	Yes	No	Yes	Yes	API	Yes	Yes	Yes
RPKI validation match	Yes	Yes	Yes	No	Yes	Yes	Yes	No	Yes	Yes	Yes
Neighbor/peer matching	Yes	Yes	Yes	No	No	Yes	Yes	No	Yes	Yes	Yes
Named policy definitions	Plugin	Yes	Yes	Yes	Partial	Yes	Yes	No	Yes	Yes	Yes
Policy chaining	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	Yes	Yes
Custom filter language	No	No	Yes	No	No	No	No	No	Yes	Yes	No
External process policy	Yes	No	No	No	No	No	No	Yes	No	No	No
Plugin-based policy	Yes	No	No	No	No	No	No	No	No	No	No

Security

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
TCP MD5 (RFC 2385)	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes
TCP-AO (RFC 5925)	No	No	No	No	No	No	No	No	No	No	No
GTSM / TTL Security	Yes	Yes	Yes	Partial	No	Yes	Yes	Yes	Yes	Yes	Yes
RPKI/RTR (RFC 6810/8210)	Yes	Yes	Yes	No	Yes	Yes	Yes	No	Yes	Yes	Yes
ASPA verification	No	Yes	Yes	No	No	No	No	No	Yes	Yes	No
Private AS removal	No	Yes	Yes	No	No	Yes	Yes	No	Yes	Yes	Yes
Privilege separation	No	No	No	No	No	No	No	No	Yes	No	No
Memory-safe language	Yes	Yes	No	Yes	Yes	No	Yes	Yes	No	No	Yes

Monitoring & Observability

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
Prometheus metrics	Yes	Yes	No	Yes	No	Yes	Yes	No	No	No	No
Structured logging (JSON)	Yes	Yes	No	Yes	No	No	No	No	No	No	No
BMP (RFC 7854)	No	Yes	Yes	Yes	Partial	Yes	Yes	No	No	Yes	Yes
MRT dump (RFC 6396)	No	Yes	Yes	No	Yes	Yes	Yes	No	Yes	Yes	Yes
Streaming route events	Yes	Yes	No	Yes	No	No	Yes	Yes	No	No	No
JSON event protocol	Yes	No	No	No	No	No	No	Yes	No	No	No
Built-in DNS resolver	Yes	No	No	No	No	No	No	No	No	No	No
Built-in PeeringDB/IRR/Cymru	Yes	No	No	No	No	No	No	No	No	No	No
Unified operational reports (show warnings / show errors)	Yes	No	Partial	No	No	Partial	No	No	Partial	Partial	Partial

Most BGP daemons expose operational issues through a mix of per-command output (show protocols all in BIRD, show bgp summary in FRR, counters in OpenBGPd) rather than a single aggregated view. Ze provides a cross- subsystem report bus: any subsystem can push warnings (state-based) or errors (event-based) onto a single place, and ze show warnings / ze show errors return the aggregate as structured JSON. The login banner reads the same source, so nothing is silently hidden. See docs/guide/operational-reports.md.

API & Programmability

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
gRPC API	No	Yes	No	Yes	Yes	Partial	Yes	No	No	No	No
REST API	No	Partial	No	No	No	Partial	No	No	No	No	No
YANG model	Yes	No	No	No	No	Partial	No	No	No	No	No
CLI tool	Yes	Yes	Yes	Partial	No	Yes	Yes	Yes	Yes	Yes	Yes
CLI JSON output	Yes	Yes	No	No	No	Yes	Yes	Yes	Yes	No	No
Runtime route injection	Yes	Yes	No	No	Yes	No	Yes	Yes	No	No	Yes
Hot reconfiguration (no restart)	Yes	Yes	Yes	Partial	No	Yes	Yes	Yes	Yes	Yes	Yes
Embeddable library	No	No	No	Yes	No	No	Yes	No	No	No	No
Plugin SDK	Yes	No	No	No	No	No	No	No	No	No	No
External process protocol	Yes	No	No	No	No	No	No	Yes	No	No	No
SSH CLI access	Yes	No	No	No	No	No	No	No	No	No	Yes

Operations

Feature	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
Config error diagnostics	Yes	Yes	No	Partial	No	No	No	No	No	No	Partial
Docker image	No	Yes	Yes	Yes	No	Yes	Yes	Yes	No	Yes	Yes
Fuzz testing	Yes	Yes	No	Yes	No	No	No	No	No	No	No
Interop test suite	Yes	Yes	No	Partial	No	No	No	No	No	No	Yes
FIB/kernel integration	No	No	Yes	Yes	No	Yes	Yes	No	Yes	Yes	Yes
Route server mode	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	Yes	Yes
Dynamic neighbors	No	No	Yes	No	Yes	Yes	Yes	No	No	Yes	Yes
Looking glass	Yes	Yes	Yes	Yes	No	No	No	No	Yes	Yes	Yes
BFD integration	No	No	Yes	No	No	Yes	No	No	No	Yes	Yes
Modular subsystem loading	Yes	No	Partial	No	No	No	No	No	No	Partial	No
Chaos testing framework	Yes	No	No	No	No	No	No	No	No	No	No
Atomic commit workflow	Yes	No	No	No	No	No	No	No	No	No	No
Schema discovery (CLI)	Yes	No	No	No	No	No	No	No	No	No	No
Healthcheck tool	Yes	No	No	Partial	No	No	No	Yes	No	No	No
PeeringDB prefix integration	Yes	No	No	No	No	No	No	No	No	No	No
Propagation benchmark tool	Yes	No	No	No	No	No	No	No	No	No	No
Update groups	Auto	No	No	No	No	Explicit	No	No	No	No	No

Update groups: Ze automatically groups peers by encoding context (ContextID) and builds each UPDATE once per group, fanning out the wire bytes to all members. No configuration needed. FRR requires explicit peer-group assignment for update group optimization. BIRD batches updates in its write loop but does not have a cross-peer build-sharing mechanism.

Best-Path Selection

ExaBGP does not perform best-path selection -- it forwards all received routes to external processes and injects routes from them. It is a route injector/receiver, not a router.

Step	Ze	rustbgpd	BIRD 3	bio-rd	RustyBGP	FRR	GoBGP	ExaBGP	OpenBGPd	BIRD 2	freeRtr
LOCAL_PREF	Yes	Yes	Yes	Yes	Yes	Yes	Yes	N/A	Yes	Yes	Yes
AS-path length	Yes	Yes	Yes	Yes	Yes	Yes	Yes	N/A	Yes	Yes	Yes
ORIGIN	Yes	Yes	Yes	Yes	Yes	Yes	Yes	N/A	Yes	Yes	Yes
MED	Yes	Yes	Yes	Yes	Yes	Yes	Yes	N/A	Yes	Yes	Yes
eBGP over iBGP	Yes	Yes	Yes	Yes	Yes	Yes	Yes	N/A	Yes	Yes	Yes
CLUSTER_LIST length	Yes	Yes	Yes	Yes	No	Yes	Yes	N/A	Yes	Yes	Yes
ORIGINATOR_ID	Yes	Yes	Yes	Yes	No	Yes	Yes	N/A	Yes	Yes	Yes
Stale route demotion (GR)	Yes	Yes	Yes	No	No	Yes	Yes	N/A	Yes	Yes	Yes
RPKI preference	Yes	Yes	Yes	No	Yes	Yes	Yes	N/A	Yes	Yes	Yes
AIGP	No	No	No	No	No	Yes	Yes	N/A	No	No	Yes
Multipath/ECMP	Partial	Partial	Yes	Yes	No	Yes	Yes	N/A	Yes	Yes	Yes

Positioning

Ze is a programmable BGP daemon and the successor to ExaBGP. It targets SDN, route injection, monitoring, and route server use cases where external processes need to interact with BGP events. A plugin architecture with YANG-modeled schemas allows extending the engine without modifying it. Lazy-parsed wire format and pool-based attribute deduplication reduce memory overhead; when encoding contexts match, UPDATEs are forwarded without re-parsing. Written in Go with an estimated 10-15% overhead vs. C/Rust (not yet benchmarked at scale; see Performance Trade-offs). ExaBGP configuration files can be migrated via ze config migrate. Built-in RPKI validation, Prometheus metrics, and structured JSON logging. The web UI automatically enriches displayed values using YANG-declared decorators (e.g., AS numbers annotated with organization names via Team Cymru DNS). No FIB integration or built-in policy language -- policy is implemented by plugins and external processes via the JSON event and text command protocol.

ExaBGP is the automation specialist. It pioneered the external-process model where BGP events are delivered as JSON to stdin/stdout of user scripts in any language. Deployed worldwide for traffic engineering, DDoS mitigation, route injection, and SDN integration. Broad address family support. Single-threaded Python, no RIB, no best-path selection, no route reflection -- by design. It is a route injector and event source, not a router.

rustbgpd is an API-first BGP daemon targeting IX route server and SDN controller use cases. It trades address family breadth for modern operational tooling (gRPC, Prometheus, structured logging, TUI, config diagnostics) and memory safety guarantees.

bio-rd is a Go BGP library and daemon originating from DE-CIX. Designed as an embeddable library for building route servers and SDN controllers. Strong route server support with RFC 9234 (BGP Roles), BMP, and ECMP. IPv4/IPv6 unicast only -- no VPN, EVPN, FlowSpec, or other address families. No Graceful Restart or Route Refresh. gRPC API with streaming RIB observation. Used in production at IXPs. Apache-2.0 license.

RustyBGP is an experimental Rust BGP daemon by the GoBGP team (OSRG). It offers a GoBGP-compatible gRPC API and multi-core design with low memory usage. Explicitly described as "very basic BGP features" -- limited address family and policy support. Useful for research and multi-core experimentation, not yet production-ready.

FRR is the most feature-complete open-source routing suite, covering BGP plus OSPF, IS-IS, PIM, and more. Best choice when you need a full routing stack with broad AFI/SAFI coverage and kernel FIB integration.

BIRD 2/3 dominates IXP route server deployments. Best-in-class memory efficiency and a powerful filter language. BIRD 3 (stable Dec 2024) adds multithreading for 5000+ peer scale. Lacks a programmatic API -- management is CLI/config-file only.

GoBGP pioneered the API-first model with gRPC as its primary interface. Broadest AFI/SAFI coverage. Higher memory and CPU usage than C implementations at scale. Best as an SDN controller or route injector rather than a high-performance router.

OpenBGPd is security-focused with privilege separation and OpenBSD heritage. Deployed at major IXPs (LINX, Netnod). Lean, reliable, and standards-compliant with strong RFC coverage including BGP Roles and Extended Messages. No programmatic API beyond the CLI socket.

freeRtr is a comprehensive router OS written entirely in Java. It implements the full routing stack (BGP, OSPF, IS-IS, RIP, EIGRP, LDP, RSVP-TE, and more) with its own TCP/IP forwarding plane that can be backed by DPDK, XDP, or P4 dataplanes. Broadest AFI/SAFI coverage of any implementation in this table, including MUP, MVPN, RTC, and VPN FlowSpec. Full best-path selection with AIGP. Has BMP, MRT dumps, BFD, and SSH CLI access. Actively developed since 2012 with 4000+ functional test cases. No programmatic API (CLI-only), no YANG model, no structured logging. The own-stack design means Docker integration requires a raw socket bridge (rawInt.bin) between the container interface and freeRtr's virtual network layer.