All,
Does anyone have a baseline on the "maximum" allocation a small to mid-sized ISP can receive from ARIN? I realize resources are scarce in IPv4 land, and I am a bit nervous to initiate the process myself without an understanding of what can/cannot be allocated. I'm not looking for anything insane, maybe a /23 or something in that realm. I'd appreciate any feedback/input any of you have – on list or off. Just looking to get a better grasp on the IPv4 climate before I start telling our people to spend money.
//warren
We recently received a /22 allocation and I believe we were told that
was the maximum at one time. However, after some period of time you are
eligible to request another.
Steve
You really need to familiarize yourself with the docs on the ARIN site that describe the request process. Capsule summary:
1. Ask for what you think you need
2. Be prepared for pushback
3. Keep good records on utilization
4. If you fill up your initial allocation, you use your utilization records to justify a subsequent allocation
And of course step 0 is to begin your IPv6 deployment plan ASAP. Yesterday would be good, a year or 2 ago would have been better. 
hth,
Doug
https://www.arin.net/policy/nrpm.html
^
There's not a predefined "maximum" allocation, there are maximums
that apply in certain circumstances; the maximum is a 3 month supply
of IP addresses that you have documented justification for, subject
to the slow-start rule (I'm assuming you can't show justified need
for a /8 or other allocation size which the free pool exhaustion
would make impossible); if you don't already have a /22, you can't
apply for a /16, for example, under the normal allocation policy.
There is a minimum allocation size, and you need to meet the
requirements shown in the policy.
To clarify, the time horizons in policy depend on the nature of the request.
ISPs are currently limited to 3 months for IPv4.
End users can get 12 months IPv4.
ISPs or end users can get up to 24 months IPv4 through the transfer process.
IPv6 does not have a clearly defined time horizon and long-term (~5 years) planning is recommended when preparing an IPv6 request.
Owen