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bird/doc/roadmap.md

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Project roadmap

Planned for 2023

SNMP AgentX plugin for BIRD status export

Allow for easier status monitoring.

BGP Monitoring Protocol (BMP)

BGP Monitoring Protocol (RFC 7854) is a protocol between a BGP speaker and a monitoring node, which is notified about route updates and neighbor state changes of the BGP speaker.

Better coverage of automatic tests

Functionality tests should cover more possible configurations and combinations. Integration tests should run automatically between different OS versions and HW architectures. Experimental support for performance regression tests.

Release 3.0-alpha1

Missing: MRT, merging

Show BFD sessions details

CLI command showing detailed information about BFD sessions state

Review and merge Babel extended next hop patches (RFC 9229)

Babel extension to allow IPv4 routes with IPv6 next hop. Patch on mailing list.

Consolidate protocol statistics

Consolidate protocol statistics, make them useful for SNMP plugin and implement 'show XX stats' command.

TCP-AO if it appears in Linux and BSD upstream

Resolve whether we should or shouldn't control the kernel key management. Design and implement our side for both Linux and BSD.

Conditional routes (v3)

Filters should be extended to allow conditional expressions based on a number of matching routes in a routing table. This would allow to specify aggregate routes using a static protocol and conditions like 'if there is at least 1000 routes from this BGP protocol, accept this default route'. This feature comes handy when a router needs to detect whether its BGP upstream is alive and working. Based of number of routes received, the router can then announce or retract a default route to OSPF, making multi-exit network routing simpler and more effective.

Aggregating routes

Requested by customer: aggregating multiple routes by a common set of attributes.

Implementation choice: the user specifies

EXPORT filter before aggregation AGGREGATE ON list of expressions to compare MERGE what to do with the remaining attributes

Example usage:

  • aggregating information from multiple internal BGP routes into one external
  • creating a multipath route from multiple BGP routes (currently done by MERGE PATHS)
  • (in future) computing a minimal route set for kernel to make forwarding faster instead of writing the received full BGP set there

PREF64 option in RA (RFC 8781)

Inform hosts about prefix used to synthesize NAT64 addresses. Requested in list: http://trubka.network.cz/pipermail/bird-users/2022-November/016401.html

Logging via UDP

Got a patch, probably never merged. May be useful. http://trubka.network.cz/pipermail/bird-users/2022-January/015893.html

BGP Tunnel Encapsulation Attribute (RFC 9012)

Packets sent to BGP next hop may be encapsulated using various tunnel technologies. Useful for L3VPN.

BGP AS Cones and ASPA support

Extend the RPKI protocol with AS Cones and ASPA loading. Implement AS Cones and ASPA validation routines. There may be some pending patches from QRator.

DHCPv6 relay agent

DHCPv6 relay agents (RFC 8415, RFC 8987) forward DHCPv6 messages between clients and servers. They also ensure that prefixes delegated by DHCPv6-PD are routable, i.e. they should generate routes for these prefixes.

Nexthop attributes and ECMP filtering

Currently we have route attributes, but with ECMP routes it is necessary to store per-nexthop data (like weight or encapsulation). We also do not have proper way to manipulate with multiple nexthops from filters. Attributes should be extended to allow per-nexthop ones and filters should be extended to allow access multiple nexthops and their attributes.

Performance accounting

Extended internal statistics about time spent in different modules of BIRD. If the route server admin checks why it takes 15 minutes to converge, this should give some basic info about performance. [MM: Internally needed by 3.0, already in progress]

MPLS support

Finalize and merge improved MPLS infrastructure (including MPLS label allocator and supporting code), improve its reconfiguration support and support for segment routing.

BGP Segment Routing Extension (RFC 8669)

Receive and announce Segment Identifiers (SIDs) for BGP next hops.

Backlog for following years

The order of these items is not significant.

Flowspec attribute filtering

Flowspec routes have many parameters, but these are not accessible from filters. Filters should be extended to access all these attributes, but first it is necessary to cleanup attribute handling in filters.

BGP Optimal Route Reflection (RFC 9107)

Implement BGP best route selection on route reflectors to adhere to POV of client, not RR. Also requested by somebody, don't remember who and when.

OSPF Traffic engineering extensions (RFC 3630)

Requested in list. May include lots of other RFC's as we have neglected this feature for a long time. http://trubka.network.cz/pipermail/bird-users/2022-January/015911.html

IPv6 preference in documentation (?)

Address world's reluctance of legacy IPv4 deprecation by updating the documentation in such a way that IPv6 is preferred and first seen.

BGP local prefix leak prevention (?)

Reject local prefixes on eBGP sessions by default to prevent leaks to public Internet. Unless explicitly enabled by config, of course.

Re-bogonization of 240/4 legacy range (?)

We shouldn't believe that every operator does the filtering right and they could simply rely on pre-2.0.10 behavior which filtered this out by default.

IPv4 multicast

Basic infrastructure for IPv4 multicast routing, including nettypes for multicast routes and multicast requests, multicast kernel protocol and IGMPv2 protocol.

PIM-BIDIR

Bidirectional PIM (RFC 5015) is a multicast routing protocol, variant of PIM-SM. It uses bidirectional shared trees rooted in Rendezvous Point (RP) to connect sources and receivers.

There is an old branch containing this. We should have merged this years ago.

Improved VRF support

BIRD has working VRF support, but it needs improvements. VRF entities should be first-class objects with explicit configuration, with a set of properties and default values (like default routing tables, or router ID) for associated protocols. Default kernel table ID should be autodetected. There should be better handling of VRF route leaking - when a route is propagated between VRFs, its nexthop should reflects that. Setup of VRFs in OS is out of scope.

Linux kernel nexthop abstraction

Netlink allows setting nexthops as objects and using them in routes. It should be much faster than conventional route update.

Protocol attributes for filtering

Filters can access route attributes, but sometimes it could be useful to access attributes of associated protocol (like neighbor-as or neighbor-ip for BGP protocol). But it would require to have internal object model (below) first, as we do not want to implement it independently for each protocol attribute.

Mutable static routes

Extension to the static protocol that would allow to add/remove/change static routes from CLI.

Multipipe

Pipe-like protocol: When a route is exported to this protocol, it runs its filter extended with capability to announce any number of new routes to any table from one filter run. Its primary purpose is to allow user-specified route aggregation and other non-linear operations.

BGP minimum route advertisement interval (MRAI)

BGP specifies minimum interval between route advertisements for the same network. This is not implemented in BIRD. It should be implemented for 3.0 to avoid unnecessary re-routing spikes.

OSPF unnumbered interfaces

The OSPFv2 protocol allows interfaces that do not have proper IP range but have peer IP addresses (like PtP links). It should be extended to also allow true unnumbered interfaces with no addresses (by using an IP address from some loopback device). This would require to have stricter separation between IP addresses and interfaces in OSPFv2.

OSPF Segment Routing Extension (RFC 8665)

MPLS label distribution using segment routing and simple OSPF extension.

MPLS Label Distribution Protocol (LDP)

Label Distribution Protocol (RFC 5036) is a protocol for establishing label-switched paths and distributing of MPLS labels between MPLS routers. These paths and labels are based on existing unlabeled routing information.

IPv6 multicast

Basic infrastructure for IPv6 multicast routing, including nettypes for multicast routes and multicast requests, multicast kernel protocol and MLDv1 protocol. Most of these (with the exception of MLDv1) is just a variant of IPv4 multicast.

IGMP/MLD multicast proxy

A simple IGMP/MLD multicast proxy, which sends IGMP/MLD requests on a configured uplink interface based on received requests on downlink interfaces, and updates associated multicast routes.

Source-specific multicast (SSM)

Infrastructure for multicasts should be extended to handle source-specific multicasts. Extend multicast nettypes to include source addresses, handle them in multicast kernel protocols and implement IGMPv3/MLDv2 protocols.

PIM-SSM

PIM-SSM is a source-specific multicast routing protocol, a subset of PIM-SM protocol (RFC 7761). It is restricted to source-specific multicasts, which eliminates many problematic parts of PIM-SM.

Seamless BFD

New version of BFD negotiation defined in RFC 7880-7886 enables faster continuity tests by dissemination discriminators by the governing protocols.

To enable seamless maintenance of single links, OSPF can advertise such a link getting down in advance, allowing to re-route. Defined in RFC 8379.

Long-term

Internal object model

We need to define explicit internal object model, where existing objects (protocols, channels, tables, routes, interfaces ...) and their properties are described in a way that allows introspection sufficient for implementing features (control protocol, CLI, filter access, perhaps reconfiguration) in a generic manner.

Generic configuration model

Configuration options are implicitly defined by the configuration parsing code. We need to define explicit configuration model independent of the parsing code and generic parsing code using that model. This will allow uniform validation of configuration properties, generic access to configuration from control protocol and possibly independent configuration backends (like one for Netconf).

New control protocol

BIRD should have a well-documented machine readable protocol. Requirements for such protocol are:

  • Generic machine readable abstract-tree representation (like CBOR)
  • Both request/reply and subscribe/notify access patterns
  • Access objects and properties using internal object model
  • In-band introspection based on internal object model

From Maria's notes:

  • CBOR-based protocol for both control and route exports
  • Python3 library with example implementation of CLI
  • (maybe) Ansible modules
  • RFC 9164: CBOR tags for IP addresses and prefices
  • RFC 9254: YANG-CBOR mapping
  • RFC 9277: Stable storage of CBOR (files)

Perhaps

IS-IS

IS-IS routing protocol is a nice-to-have alternative to OSPF.

BGPsec

BGPsec (RFC 8205) is a new path security extension to BGP.

PIM-SM

PIM-SM (RFC 7761) is a prevailing multicast routing protocol, but more complicated than planned PIM-BIDIR and PIM-SSM.

Netconf

Network Configuration Protocol (RFC 6241) is a XML/JSON protocol for configuration management of network devices. It would benefit from generic configuration model (above).

NetConf overlay

Machine-friendly config file editor daemon (standalone) with standard NetConf interface on one side and BIRD config file + reconfiguration requests on the other side. Python3 seems to be better choice than C for this kind of work.

Backend for 802.11r

Let's assume a bunch of boxes, all having some public wifi APs and some (secure) uplinks. Design and implement an automatic backbone protocol to allow for simple almost-zeroconf setup of e.g. a conference room or train / bus public wifi or even a local home network, all with hostapd seamlessly transferring clients between APs via 802.11r. Possible collab with Turris.

BFD Multipoint Connectivity

Checking whether multiple "receivers" can communicate with a single "sender". Possibly useful after merging PIM-BIDIR and implementing other PIMs. RFC 8562-8563.

BGP-LS allows to transport information about network topology across BGP links. This should help e.g. to run traffic-engineering between more confederated ASs. Also needed to implement Seamless BFD on BGP: RFC 9247

Locator/ID Separation Protocol

LISP intends to break up addressing to Routing Locators and Endpoint Identifiers. This may help multihoming networks in future. RFC 9299-9306.

Backend for IPv6 Multihoming without BGP

Implement and configure BIRD in such a way that local nodes are seamlessly connected to the Internet via multiple upstreams, using Network Prefix Translation and other techniques. Possible collab with Turris.

Minor

  • RFC 8510: OSPF LLS Extension for Local Interface ID Advertisement
  • RFC 8538: BGP Graceful Restart Hard Reset
  • RFC 8326: BGP Graceful Session Shutdown Community auto-apply
  • RFC 8962: Become part of the IETF Protocol Police
  • RFC 9072: Extended Optional Parameters Length for BGP OPEN Message
  • RFC 9339: OSPF Reverse Metric