IRR-clueful person at 3356?

Hi folks,

Sorry for the extremely broad email but I'm trying to sort out an IRR
issue regarding automatic filter generation at Level(3) on behalf of a

The telemetry I'm getting (thirdhand and believed to originate from
first line support) suggests that both Level(3)'s direct customer and
any downstreams of that customer need to be in the same IRR component.
If true this would be a rather startling shortcoming of their filter
generation software and at odds with the whole point of having
multiple components to the IRR system.

Anyone got any pointers or help? Email to has not
gotten us anywhere, but I was not the one who sent it and can't
guarantee that the right questions were asked.



Can't say for sure if it's true, but I've been told the same thing by Level3 support.

L3 can be tricky with IRR especially if you have objects split across multiple IRR databases.

This should help with what filters you want them to put on:

You can test before using:

whois -h "RIPE::YOUR-AS-SET -searchpath=RIPE;ARIN;RADB -recurseok -warnonly"


That's the sort of thing we have in Europe, downstream customer need to be
in your AS-SET for filtering purposes

Thanks to all who reached out to me in private email and on IRC.

Here's the thumbnail explanation of how to do it (so some future
searcher doesn't curse me for not summarizing to the list).

By default Level(3) only searches one IRR component for you. I can
understand why one would want to scope things this way but it sure was
confusing. It's possible to have one's searchpath set to look in
multiple IRR components explicitly (or "*" if you want more standard
behavior) - these parameters are hinted at in the output from "whois
-h help" but you need someone in tech support to
set this up for you in 3Scape; don't expect the first line guys to be
able to help you beyond telling you that your update failed.

There's another way though - Level(3) uses an extension to RPSL that
allows one to explicitly state sources in the as-set like so:

   "remarks:" is normally just a remark and not evaluated, BUT...
   "remarks: Level3 members:" is a magic construct that will cause the
   rest of the line to be evaluated by Level(3) as one or more
   "IRRCOMPONENT::AS-OR-AS-SET" pairs. Apparently unqualified
   AS-OR-AS-SET values are allowed too, presumably to default to either
   whatever your normal pull-from IRR component is or from LEVEL3, but it
   looks as if one can't go wrong by explicitly stating each pair.

Comcast and Yipes both have very nice as-sets that can be used as
cheat sheets for how the grammar works:

whois -h as-cbc
whois -h as-yipes

(careful with as-yipes - you get two objects back, one with a source
of LEVEL3 and one with a source of RADB - it's the LEVEL3 one that you
are interested in).

Disclaimer: I haven't tested this all the way yet. The origin AS
expands right and the friend's upstream has been updated and we're
just waiting for mirroring to happen. If there's nothing further from
me in this thread in a couple of days then it worked. :slight_smile: