IPv6 Default Allocation - What size allocation are you giving out

Faisal Imtiaz faisal at snappytelecom.net
Thu Oct 9 04:18:03 UTC 2014


Awesome, Thank you Royce, the missing piece has clicked in place... 

:) 

Faisal Imtiaz 
Snappy Internet & Telecom 
7266 SW 48 Street 
Miami, FL 33155 
Tel: 305 663 5518 x 232 

Help-desk: (305)663-5518 Option 2 or Email: Support at Snappytelecom.net 

----- Original Message -----

> From: "Royce Williams" <royce at techsolvency.com>
> To: "Faisal Imtiaz" <faisal at snappytelecom.net>
> Cc: "Sam Silvester" <sam.silvester at gmail.com>, "NANOG" <nanog at nanog.org>
> Sent: Thursday, October 9, 2014 12:14:51 AM
> Subject: Re: IPv6 Default Allocation - What size allocation are you giving
> out

> On Wed, Oct 8, 2014 at 8:07 PM, Faisal Imtiaz < faisal at snappytelecom.net >
> wrote:

> > Like I said, this was my understanding.... I am glad that it is being
> > pointed
> > out to be in-correct....
> 

> > I don't have a reason for why a /64 as much as I also don't have any reason
> > Why NOT....
> 

> > So, let me ask the question in a different manner...
> 
> > What is the wisdom / reasoning behind needing to give a /56 to a
> > Residential
> > customer (vs a /64).
> 

> Quoting RFC6177 (successor to RFC3177):

> While the /48 recommendation does simplify address space management
> for end sites, it has also been widely criticized as being wasteful.
> For example, a large business (which may have thousands of employees)
> would, by default, receive the same amount of address space as a home
> user, who today typically has a single (or small number of) LAN and a
> small number of devices (dozens or less). While it seems likely that
> the size of a typical home network will grow over the next few
> decades, it is hard to argue that home sites will make use of 65K
> subnets within the foreseeable future. At the same time, it might be
> tempting to give home sites a single /64, since that is already
> significantly more address space compared with today's IPv4 practice.
> However, this precludes the expectation that even home sites will
> grow to support multiple subnets going forward. Hence, it is
> strongly intended that even home sites be given multiple subnets
> worth of space, by default. Hence, this document still recommends
> giving home sites significantly more than a single /64, but does not
> recommend that every home site be given a /48 either.

> A change in policy (such as above) would have a significant impact on
> address consumption projections and the expected longevity for IPv6.
> For example, changing the default assignment from a /48 to /56 (for
> the vast majority of end sites, e.g., home sites) would result in a
> savings of up to 8 bits, reducing the "total projected address
> consumption" by (up to) 8 bits or two orders of magnitude. (The
> exact amount of savings depends on the relative number of home users
> compared with the number of larger sites.)

> The above-mentioned goals of RFC 3177 can easily be met by giving
> home users a default assignment of less than /48, such as a /56.

> Royce



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