On 24 Oct 2017, at 14:18, Rob Evans <rhe@nosc.ja.net> wrote:

Full agreement with Nick, the (controlled) announcement or otherwise
of an IXP prefix is not a registry policy issue.

Cheers,
Rob

Another +1 here with Nick’s email. There are good reasons to not announce the peering LAN prefix,
but there are also good reasons to announce it. In the AMS-IX case, we have so many
networks connected that:

1. Customers announce it inadvertently anyhow
2. Since 1. is the operational reality (which is unrealistic to stop anytime soon, if ever), 
we prefer (also) announcing it ourselves, in the hopes that traffic at least goes through
its “legitimate" originator.

From my point of view, RIPE could offer reasons for both options, as to educate
in the matter, contributing in a way so IXPs can make an informed decision.

Kind regards,
Aris
AMS-IX