nanog mailing list archives

Re: "Tactical" /24 announcements


From: Lukas Tribus <lukas () ltri eu>
Date: Wed, 11 Aug 2021 14:05:13 +0200

On Wed, 11 Aug 2021 at 12:24, Tom Hill <tom () ninjabadger net> wrote:

On 10/08/2021 07:15, Lukas Tribus wrote:
Are there any big networks that drop or penalize announcements like this?
It's possible you could get your peering request denied for this. I
have put *reasonable* prefix aggregation into peering requirements for
some years now. If you are a small eyeball network with 8192 IP
addresses and originate 32 /24's, that is *not* reasonable.

It is quite an issue when a network tries to programmatically filter-out
the /24 more-specifics advertisements made from an allocated, .e.g, /20.

Such anti-disaggregation/save-my-TCAM efforts really do not work, and
will spawn all manner of support tickets. I'm saying this in the hope
that it may prevent someone from reading this thread and concluding that
it may be a good idea to try. It is not.

For the record: I did not suggest anything like this.

Denying peering requests due to lack of *reasonable* prefix
aggregation does not mean installing fancy, impossibile to maintain
prefix-lists on transit ingress. I agree with you here, that would be
very bad.

This save-my-TCAM effort is successful when the peer on the other site
actually realizes that there are consequences to decisions like this
and reverts it, which is a long shot, sure, but at least I'm not
encouraging this. I don't get to dictate other peoples configurations.
I do get to decide who is directly exchanging traffic with my network
and who isn't.


lukas


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