nanog mailing list archives

Re: "Tactical" /24 announcements


From: David Bass <davidbass570 () gmail com>
Date: Wed, 18 Aug 2021 20:05:55 -0400

I'm also in the externally managed space...very cool tool though.  I love
the idea of distributing some of this functionality.

Are you also exporting and managing this data outside?

On Tue, Aug 17, 2021 at 12:23 PM Ben Maddison via NANOG <nanog () nanog org>
wrote:

Hi Saku,

On 08/17, Saku Ytti wrote:
I share your confusion Randy. It seems like perhaps Jakob answered a
slightly different question and his answer is roughly.

a) Use this as-set feature to ensure valid set of ASNs from given peer
b) Validate prefix using RPKI (I'm assuming with rejecting unknowns
and invalids)
c) Don't punch in prefix-lists anywhere

Which in theory works, but in practice it does not, as RPKI validity
cover is incomplete.

This, and (more fundamentally) RPKI-breakage gets translated into a
dataplane
outage.

Somewhat related, when JNPR implemented RTR the architecture was
planned so that the RTR implementation itself isn't tightly coupled to
RPKI validity. It was planned day1 that customers could have multiple
RTR setups feeding prefixes and the NOS side could use these for other
purposes too. So technically JNPR is mostly missing CLI work to allow
you to feed prefix-lists dynamically over RTR, instead of punching
them in vendor-specific way in config.

We already do essentially this on arista EOS using a custom agent.

It runs under the EOS process supervisor and calls home to a REST-API
wrapper around bgpq3. It looks for specific config lines to work out
which prefix lists to build, and then fetches them on a configurable
interval.

This has been in production for a year or two, without major incident.
It's all open source, available at
https://github.com/wolcomm/eos-prefix-list-agent.
Pull-requests
<https://github.com/wolcomm/eos-prefix-list-agent.Pull-requests> welcomed
;-)

I'm in the middle of writing the equivalent tool for junos at the
moment. Assuming that it works, we'll open source that too.

HTH,

Ben


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