Policy 2001-2: Reassignments to multihomed downstream customers

Status: Adopted - NRPM Section

Tracking Information

Discussion Tracking

Mailing List:

Formal introduction on PPML on 24 September 2001

Public Policy Mailing List

ARIN Public Policy Meeting:


ARIN Advisory Council:

30 October 2001

ARIN Board of Trustees:

11 December 2001
22 January 2002






Under normal circumstances an ISP is required to determine the prefix size of their reassignment to a downstream customer according to the guidelines set forth in RFC 2050. Specifically, a downstream customer justifies their reassignment by demonstrating they have an immediate requirement for 25% of the IP addresses being assigned, and that they have a plan to utilize 50% of their assignment within one year of its receipt. This policy allows a downstream customer's multi-homing requirement to serve as justification for a /24 reassignment from their upstream ISP, regardless of host requirements. Downstream customers must provide contact information for all of their upstream providers to the ISP from whom they are requesting a /24. The ISP will then verify the customer's multi-homing requirement and may assign the customer a /24, based on this policy. Customers may receive a /24 from only one of their upstream providers under this policy without providing additional justification.

ISPs may demonstrate they have made an assignment to a downstream customer under this policy by supplying ARIN with the information they collected from the customer, as described above, or by identifying the AS number of the customer. This information may be requested by ARIN staff when reviewing an ISP's utilization during their request for additional IP addresses space.