.. _rpki:

####
RPKI
####

.. pull-quote::

   There are two types of Network Admins who deal with BGP, those who have
   created an international incident and/or outage, and those who are lying

   -- `tweet by EvilMog`_, 2020-02-21

:abbr:`RPKI (Resource Public Key Infrastructure)` is a framework :abbr:`PKI
(Public Key Infrastructure)` designed to secure the Internet routing
infrastructure. It associates BGP route announcements with the correct
originating :abbr:`ASN (Autonomus System Number)` which BGP routers can then
use to check each route against the corresponding :abbr:`ROA (Route Origin
Authorisation)` for validity. RPKI is described in :rfc:`6480`.

A BGP-speaking router like VyOS can retrieve ROA information from RPKI
"Relying Party software" (often just called an "RPKI server" or "RPKI
validator") by using :abbr:`RTR (RPKI to Router)` protocol. There are several
open source implementations to choose from, such as NLNetLabs' Routinator_
(written in Rust), Cloudflare's GoRTR_ and OctoRPKI_ (written in Go), and
RIPE NCC's RPKI Validator_ (written in Java). The RTR protocol is described
in :rfc:`8210`.

.. tip::
  If you are new to these routing security technologies then there is an
  `excellent guide to RPKI`_ by NLnet Labs which will get you up to speed
  very quickly. Their documentation explains everything from what RPKI is to
  deploying it in production. It also has some 
  `help and operational guidance`_ including "What can I do about my route 
  having an Invalid state?"

***************
Getting started
***************

First you will need to deploy an RPKI validator for your routers to use. The
RIPE NCC helpfully provide `some instructions`_ to get you started with
several different options.  Once your server is running you can start
validating announcements.

Imported prefixes during the validation may have values:

  valid
    The prefix and ASN that originated it match a signed ROA. These are
    probably trustworthy route announcements.

  invalid
    The prefix or prefix length and ASN that originated it doesn't
    match any existing ROA. This could be the result of a prefix hijack, or
    merely a misconfiguration, but should probably be treated as
    untrustworthy route announcements.

  notfound
    No ROA exists which covers that prefix. Unfortunately this is the case
    for about 80% of the IPv4 prefixes which were announced to the :abbr:`DFZ
    (default-free zone)` at the start of 2020

.. note::
  If you are responsible for the global addresses assigned to your
  network, please make sure that your prefixes have ROAs associated with them
  to avoid being `notfound` by RPKI. For most ASNs this will involve
  publishing ROAs via your :abbr:`RIR (Regional Internet Registry)` (RIPE
  NCC, APNIC, ARIN, LACNIC or AFRINIC), and is something you are encouraged
  to do whenever you plan to announce addresses into the DFZ.

  Particularly large networks may wish to run their own RPKI certificate
  authority and publication server instead of publishing ROAs via their RIR.
  This is a subject far beyond the scope of VyOS' documentation. Consider
  reading about Krill_ if this is a rabbit hole you need or especially want
  to dive down.

Features of the Current Implementation
======================================

In a nutshell, the current implementation provides the following features:

* The BGP router can connect to one or more RPKI cache servers to receive
  validated prefix to origin AS mappings. Advanced failover can be implemented
  by server sockets with different preference values.

* If no connection to an RPKI cache server can be established after a
  pre-defined timeout, the router will process routes without prefix origin
  validation. It still will try to establish a connection to an RPKI cache
  server in the background.

* By default, enabling RPKI does not change best path selection. In particular,
  invalid prefixes will still be considered during best path selection. However,
  the router can be configured to ignore all invalid prefixes.

* Route maps can be configured to match a specific RPKI validation state. This
  allows the creation of local policies, which handle BGP routes based on the
  outcome of the Prefix Origin Validation.

* Updates from the RPKI cache servers are directly applied and path selection is
  updated accordingly. (Soft reconfiguration must be enabled for this to work).

*************
Configuration
*************

.. cfgcmd:: set protocols rpki polling-period <1-86400>

  Define the time interval to update the local cache

  The default value is 300 seconds.

.. cfgcmd:: set protocols rpki cache <address> port <port>

  Defined the IPv4, IPv6 or FQDN and port number of the caching RPKI caching
  instance which is used.

  This is a mandatory setting.

.. cfgcmd:: set protocols rpki cache <address> preference <preference>

  Multiple RPKI caching instances can be supplied and they need a preference in
  which their result sets are used.

  This is a mandatory setting.

SSH
===

Connections to the RPKI caching server can not only be established by HTTP/TLS
but you can also rely on a secure SSH session to the server. To enable SSH,
first you need to create an SSH client keypair using ``generate ssh
client-key /config/auth/id_rsa_rpki``. Once your key is created you can setup
the connection.

.. cfgcmd:: set protocols rpki cache <address> ssh username <user>

  SSH username to establish an SSH connection to the cache server.

.. cfgcmd:: set protocols rpki cache <address> ssh known-hosts-file <filepath>

  Local path that includes the known hosts file.

.. cfgcmd:: set protocols rpki cache <address> ssh private-key-file <filepath>

  Local path that includes the private key file of the router.

.. cfgcmd:: set protocols rpki cache <address> ssh public-key-file <filepath>

  Local path that includes the public key file of the router.

.. note:: When using SSH, known-hosts-file, private-key-file and public-key-file
  are mandatory options.

*******
Example
*******

We can build route-maps for import based on these states. Here is a simple
RPKI configuration, where `routinator` is the RPKI-validating "cache"
server with ip `192.0.2.1`:

.. code-block:: none

  set protocols rpki cache 192.0.2.1 port '3323'
  set protocols rpki cache 192.0.2.1 preference '1'

Here is an example route-map to apply to routes learned at import. In this
filter we reject prefixes with the state `invalid`, and set a higher
`local-preference` if the prefix is RPKI `valid` rather than merely
`notfound`.

.. code-block:: none

  set policy route-map ROUTES-IN rule 10 action 'permit'
  set policy route-map ROUTES-IN rule 10 match rpki 'valid'
  set policy route-map ROUTES-IN rule 10 set local-preference '300'
  set policy route-map ROUTES-IN rule 20 action 'permit'
  set policy route-map ROUTES-IN rule 20 match rpki 'notfound'
  set policy route-map ROUTES-IN rule 20 set local-preference '125'
  set policy route-map ROUTES-IN rule 30 action 'deny'
  set policy route-map ROUTES-IN rule 30 match rpki 'invalid'

Once your routers are configured to reject RPKI-invalid prefixes, you can
test whether the configuration is working correctly using the `RIPE Labs RPKI
Test`_ experimental tool.

.. stop_vyoslinter

.. _tweet by EvilMog: https://twitter.com/Evil_Mog/status/1230924170508169216
.. _Routinator: https://www.nlnetlabs.nl/projects/rpki/routinator/
.. _GoRTR: https://github.com/cloudflare/gortr
.. _OctoRPKI: https://github.com/cloudflare/cfrpki#octorpki
.. _Validator: https://www.ripe.net/manage-ips-and-asns/resource-management/rpki/tools-and-resources
.. _some instructions: https://labs.ripe.net/Members/tashi_phuntsho_3/how-to-install-an-rpki-validator
.. _Krill: https://www.nlnetlabs.nl/projects/rpki/krill/
.. _RIPE Labs RPKI Test: https://sg-pub.ripe.net/jasper/rpki-web-test/
.. _excellent guide to RPKI: https://rpki.readthedocs.io/
.. _help and operational guidance: https://rpki.readthedocs.io/en/latest/about/help.html

.. start_vyoslinter