[186983] in North American Network Operators' Group
Re: Deploying IPv6 in an ISP network [ was: Best Source for ARIN
daemon@ATHENA.MIT.EDU (Owen DeLong)
Mon Jan 11 19:53:18 2016
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <20160112002109.GA20890@bamboo.slabnet.com>
Date: Mon, 11 Jan 2016 16:52:06 -0800
To: Hugo Slabbert <hugo@slabnet.com>
Cc: North American Network Operators' Group <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
> On Jan 11, 2016, at 16:21 , Hugo Slabbert <hugo@slabnet.com> wrote:
>=20
> On Mon 2016-Jan-11 20:16:21 +0000, Shon Elliott =
<selliott@getunwired.com> wrote:
>=20
>> I also am interested in where people are finding blocks of /22 or =
smaller just in case. We have some blocks from Level 3, but eventually, =
we're going to be out.
>>=20
>> That being said, we did get our IPv6 /32 allocation from ARIN. If =
anyone has any ideas on how to properly deploy this in an ISP =
environment, I'd love to learn. I've read some whitepapers on the =
subject, but most of those deal with enterprise based networks, and not =
so much as a service provider.
Step 1: Figure out what size block you should have requested and go back =
and get that.
Sure, that=E2=80=99s a little bit flip, but I=E2=80=99m actually =
serious. Most ISPs will need more than a /32 unless they are fairly =
trivial.
Instead of starting from a /32 and figuring out how to squeeze your =
customers into it, you should start from the number of end-sites you =
expect to serve from your largest serving site (POP or other aggregation =
point in your network) in the next, say 5 years.
Round that up to a nibble boundary with 25% free.
For example, if your largest site has fewer than 192 end-sites served, 8 =
bits is enough. If you have 192 or more but less than 3072, 12 bits is =
enough.
IF you have a million customers in your largest serving site, you=E2=80=99=
re looking at 20 bits or more per serving site.
Next, figure out the number of serving sites you expect to have in the =
next 5 years and round that up to a nibble boundary (again with 25% =
free).
So, if you expect to have more than 12, but fewer than 192 serving =
sites, 8 bits is enough. Fewer than 12, you can get by with 4 bits. =46rom=
192-3071, 12 bits.
Now, add those two sets of bits together and subtract from 48.
That=E2=80=99s your prefix size that you need to ask for.
I=E2=80=99m quite certain you can get that size prefix if you=E2=80=99ve =
done the exercise correctly because that=E2=80=99s exactly how the =
policy is written.
Owen
