nanog mailing list archives

Re: Questions about anycasting setup


From: Mehmet Akcin <mehmet () akcin net>
Date: Fri, 9 Mar 2012 00:23:55 -0800


On Mar 9, 2012, at 12:11 AM, Elmar K. Bins wrote:

 3. IPv6! - Is /32 is standard? We have only one /32
 allocation from ARIN and thus if using /32 seems like hard deal - we have
 to likely get another /32 just for anycasting? or we can use /48 without
 issues? Also, is /48 a good number for breaking /32 so that we can do /48
 announcements from different datacenters in simple uni casting setup?

A /48 is quite reasonable.  Announcing a whole /32 just for your anycast service would be wasteful.

Why? It's simply another prefix, no matter how big. It might look
wasteful, but if *that* is the allocation you *have*, it's the
one you ought to use.

One should be careful - people do filter on allocation lengths, so
breaking out a /48 out of a /32 allocation and advertising it on its
own can lead to it being filtered.

if you know anyone who is filtering /48 , you can start telling them to STOP doing so as a good citizen of internet6.

I agree with Woody anything more than /48 for anycast is waste.

mehmet

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