[193435] in North American Network Operators' Group
Re: Questions on IPv6 deployment
daemon@ATHENA.MIT.EDU (William Herrin)
Tue Jan 17 16:02:10 2017
X-Original-To: nanog@nanog.org
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In-Reply-To: <CAPDTRiis85k9vC22WqOt77G+qbWqFJD8eQ9O0Yi=XNFAdQHQ_Q@mail.gmail.com>
From: William Herrin <bill@herrin.us>
Date: Tue, 17 Jan 2017 16:01:40 -0500
To: Michael Still <stillwaxin@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Tue, Jan 17, 2017 at 12:48 PM, Michael Still <stillwaxin@gmail.com> wrote:
> http://nabcop.org/index.php/IPv6_Subnetting
That's overall good advice. I quibble with a couple of points:
1. If you plan to use a /126 on a point to point and can't imagine how
you would use a /64 on that point to point, don't allocate a /64. Odds
are that by the time you can imagine some way to use a /64 there, the
details will require you to assign a new block anyway.
Why be concerned about resource consumption? Because it's a good
habit. Don't overdo it, IPv6 is not resource constrained the way IPv4
is, but shrewd use of available resources is a good habit even when
resources are plentiful.
2. Make all your point to points /124. That will work for all your
point to points. Serial or ethernet. Even the ethernets which have two
high-availability routers on both ends along with the failover address
needing a total of 6 IPs plus 1 for your troubleshooting laptop.
Configuring /124 every time allows you to standardize your
configuration, the same way /64 standardizes the netmask on a LAN
deployment.
One additional point not brought up:
Minimum assignment to a customer: /60. Never ever /64 or /128. How
much more than a /60 you choose as your minimum is up to you. Common
choices are /56 and /48. But never, ever less than a /60. Your
customer will want to deploy a /64 to each LAN. And there are so many
cases where he'll want to deploy more than one LAN.
I've noticed a lot of hosting providers getting this wrong. Some of
your customers do create VPNs on their VPC you know.
Regards,
Bill Herrin
--
William Herrin ................ herrin@dirtside.com bill@herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
