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.. _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 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), OpenBSD's rpki-client_ (written in C), and StayRTR_ (written
in Go). 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. NLnet
Labs provides a collection of software_ you can compare and settle on one.
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 40%-50% of the prefixes which were announced to the :abbr:`DFZ
(default-free zone)` at the start of 2024.
.. 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 expire-interval <600-172800>
Set the number of seconds the router waits until the router
expires the cache.
The default value is 7200 seconds.
.. cfgcmd:: set protocols rpki retry-interval <1-7200>
Set the number of seconds the router waits until retrying to connect
to the cache server.
The default value is 600 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 TCP using
the RTR protocol but you can also rely on a secure SSH session to the server.
This provides transport integrity and confidentiality and it is a good idea if
your validation software supports it. 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 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, 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 Cloudflare's test_
website. Keep in mind that in order for this to work, you need to have no
default routes or anything else that would still send traffic to RPKI-invalid
destinations.
.. stop_vyoslinter
.. _tweet by EvilMog: https://twitter.com/Evil_Mog/status/1230924170508169216
.. _Routinator: https://www.nlnetlabs.nl/projects/rpki/routinator/
.. _Krill: https://www.nlnetlabs.nl/projects/rpki/krill/
.. _excellent guide to RPKI: https://rpki.readthedocs.io/
.. _help and operational guidance: https://rpki.readthedocs.io/en/latest/about/help.html
.. _rpki-client: https://www.rpki-client.org/
.. _StayRTR: https://github.com/bgp/stayrtr/
.. _software: https://rpki.readthedocs.io/en/latest/ops/tools.html#relying-party-software
.. _test: https://isbgpsafeyet.com/
.. start_vyoslinter
|
