The American Registry for Internet Numbers or
ARIN has put out a great little
PDF you can download on how to get started with getting your first IPv6 allocation. For those who have not done this it can be useful to have an outline about what to expect in the process and this provides that.
It is interesting to note that they give the same site to prefix allocation chart as their website which is outlined below:
| Number of Sites |
Prefix Block Size |
| 1 |
/48 |
| 2-12 |
/44 |
| 13-192 |
/40 |
| 193-3,072 |
/36 |
| 3,072 - 49,152 |
/32 |
You can find the details for how this actually works on the
ARIN website.
I would expect most enterprises to fit in the /40 to /36 category as
ARIN's definition of a site is relatively broad. They did this
intentionally and as you can see in the definitions that follow, you can
argue your single work from home user would classify as a site.
From
ARIN's website:
"6.5.8.2.1. Standard sites
A site is a discrete location that is part of an organization’s
network. A campus with multiple buildings may be considered
as one or multiple sites, based on the implementation of its
network infrastructure. For a campus to be considered as
multiple sites, reasonable technical documentation must be
submitted describing how the network infrastructure is
implemented in a manner equivalent to multiple sites.
An organization may request up to a /48 for each site in its
network, and any sites that will be operational within 12
months.
6.5.8.2.2. Extra-large sites
In rare cases, an organization may request more than a /48 for an
extra-large site which requires more than 16,384 /64 subnets.
In such a case, a detailed subnet plan must be submitted for
each extra-large site in an organization’s network. An
extra-large site qualifies for the next larger prefix when
the total subnet utilization exceeds 25%. Each extra-large
site will be counted as an equivalent number of /48 standard
sites."
Remember, if you run labs, dev and test networks that might have to simulate an entire site then you need to include each of those as sites and not as a single /64 subnet in your design and request to ARIN. Otherwise you will not have enough address space to build out those test environments that you might require and you will have to go back to request address space.
- Ed
