From Internet Service Providers (ISPs)

ARIN takes guidance from allocation policies set forth in RFC 2050 and guidelines outlined in Internet Protocol (IP) Allocation Guidelines for Internet Service Providers (ISPs). Consistent with the policies described in those documents and the practices of other Internet Registries, ARIN issues initial allocations of prefixes no longer than /19, unless meeting the multi-homed criteria listed below. This document defines multi-homing as receiving full-time connectivity from more than one ISP, and which has one or more routing prefixes announced by at least two of its ISPs.

This requirement is due to technical and implementation constraints on the Internet routing system necessitating that ISPs implement practices such as prefix filtering.

In order to receive an initial allocation from ARIN, ISPs must meet the following criteria:

Multi-homed organizations that have efficiently utilized a /21 and;

• provide documentation justifying additional address space (see #3,4 below)

• agree to renumber out of the /21 within 18 months and return the space to its original provider will meet the requirements for obtaining a /20 from a reserved /19. The /20 must be used for renumbering the previously allocated block. The organization will be allowed to temporarily announce the entire /19. The reserved address space will be valid for 18 months. If the organization has not justified the remainder of the /19 by the end of the 18 months, it will no longer be held in reserve and will be considered available to be assigned to another entity. At that time only the /20 can be announced.
  

Those ISPs that do not meet the requirements listed above must adhere to the following guidelines:

1. The efficient utilization of an entire previously allocated /19 from their upstream Internet Service Provider. This /19 allocation does not have to be contiguous address space. The ISP must meet the requirement of efficient use of 32 C's. For example, if an ISP holds a smaller allocation, such as 24 C's, from their upstream provider the ISP would not meet the minimum requirements of a /19.
   
2. Demonstration to ARIN of the efficient use of Internet Protocol (IP) address space allocations. To justify a further allocation, the ISP must provide to ARIN appropriate documentation, including assignment histories, to verify efficient use of current allocations.
   
3. Provision of reassignment information on the entire previously allocated block(s) via the Shared WHOIS Project (SWIP) or through the use of an RWHOIS server. This information must be visible via WHOIS prior to submitting a request for a new allocation.
   
4. Supply information detailing your three-month requirement for a minimum allocation of /19.
   

NOTE: ISPs must use their provider/maintainer ID to provide reassignment information via SWIP or RWHOIS. If you do not have a provider/maintainer ID or do not know your assigned ID, contact ARIN by E-mail at reassign@arin.net. Include your company name and list IP addresses currently held by your organization. Based on this information, ARIN can send you your provider/maintainer ID.

This may include renumbering out of your upstream ISP's space. The initial allocation from ARIN will be a /19 unless an acceptable, detailed justification for a larger block is supplied.

For information on reassigning IP address space, please read the guidelines in the pertinent sections of RFC 2050.

If you meet the above criteria, please complete the ISP Network template. Submit the template to ARIN via E-mail at hostmaster@arin.net.