Small IX IP Blocks

Mark Tinka mark.tinka at
Sun Apr 5 04:46:59 UTC 2015

On 5/Apr/15 02:35, Mike Hammett wrote:
> Okay, so I decided to look at what current IXes are doing. 
> It looks like AMS-IX, Equinix and Coresite as well as some of the smaller IXes are all using /64s for their IX fabrics. Seems to be a slam dunk then as how to handle the IPv6. We've got a /48, so a /64 per IX. For all of those advocating otherwise, do you have much experience with IXes? Multiple people talked about routing. There is no routing within an IX. I may grow, but an IX in a tier-2 American city will never scale larger than AMS-IX. If it's good enough for them, it's good enough for me. 
> Back to v4, I went through a few pages of PeeringDB and most everyone used a /24 or larger. INEX appears to use a /25 for each of their segments. IX Australia uses mainly /24s, but two locations split a /24 into /25s. A couple of the smaller single location US IXes used /25s and /26s. It seems there's precedent for people using smaller than /24s, but it's not overly common. Cash and address space preservation. What does the community think about IXes on smaller than /24s? 

Your main issue with a smaller IPv4 subnet is when you grow, you'll end
up having to renumber. This has hit some large exchange points in the
recent past.

Of course, it's easy to say that you won't grow beyond X members now,
but there's no knowing how that will go if you're working hard at your


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