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Re: IPv6 /48 advertisements
From: Blake Dunlap <ikiris () gmail com>
Date: Wed, 18 Dec 2013 10:32:16 -0600

Regardless of the carriers, you'll find most ASs on the internet only
listen to /48 or larger. So even if you get your prefixes accepted by your
provider, don't assume you can get anywhere, or have your packets not fall
in to uRPF blackholes randomly without a larger aggregate announcement.


On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore <
edward.dore () freethought-internet co uk> wrote:

If you’re talking about announcing each location separately, then RIPE
have a couple of useful articles about prefix visibility on Ripe Labs:


Otherwise I guess you’ll need to talk to your chosen carrier(s) about
aggregating your space for you, which will come down to their policies on
what routes they will carry internally.

Edward Dore
Freethought Internet

On 18 Dec 2013, at 16:11, Cliff Bowles <cliff.bowles () apollogrp edu> wrote:

I accidentally sent this to nanog-request yesterday. I could use some
feedback from anyone that can help, please.

Question: will carriers accept IPv6 advertisements smaller than /48?

Our org was approved a /36 based on number of locations. The bulk of
those IPs will be in the data centers. As we were chopping up the address
space, it was determined that the remote campus locations would be fine
with a /60 per site. (16 networks of /64). There are usually less than 50
people at the majority of these locations and only about 10 different
functional VLANs (Voice, Data, Local Services, Wireless, Guest Wireless,

Now, there has been talk about putting an internet link in every campus
rather than back hauling it all to the data centers via MPLS. However, if
we do this, then would we need a /48 per campus? That is massively
wasteful, at 65,536 networks per location.  Is the /48 requirement set in
stone? Will any carriers consider longer prefixes?

I know some people are always saying that the old mentality of
conserving space needs to go away, but I was bitten by that IPv4 issue back
in the day and have done a few VLSM network overhauls. I'd rather not
massively allocate unless it's a requirement.

Thanks in advance.


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