If your company obtained its IP address space before 1997, you have probably received several letters from the American Registry for Internet Numbers Ltd. (ARIN) encouraging you to enter into a contractual agreement to protect the IP address. But should you sign it?
ARIN's contract is called the Legacy Registration Services Agreement (Legacy RSA). It proposes to give companies contractual guarantees, including grandfathering of certain protected rights; continued use -- at no extra charge, at least for now -- of IP address services like "in-addr" and "whois" listings; reduced annual fees compared with those of ARIN's regular IP address holders; and future fee waivers, in exchange for returning unused IP address space.
But be careful -- there are several issues you should consider before signing up for this.
The information and advice in this piece are based on my experience advising legacy address holders in connection with their participation in the Legacy RSA program. I've been working with legacy holders since the beginning of the program in 2007, and my representation has included leading negotiations with ARIN on behalf of clients. As part of this effort, I've also had informal consultations with ARIN's lead counsel and its directory of registry services.
Some history
Since Dec. 22, 1997, ARIN has been the authorized administrator of IPv4 address allocations and services in North America. ARIN is one of five regional Internet address registries, all operating under the authority of ICANN. ARIN obtained this authorization through a delegation from InterNIC, which previously handled the assignment and administration of domain names and IP addresses. (InterNIC itself was organized in 1993 by the National Science Foundation and Network Solutions Inc., a private company awarded the government contract to provide IP address services.)
Before 1993, IP addresses were assigned through the Internet Assigned Numbers Authority (IANA).
Under the rules of InterNIC and IANA, Internet service providers and certain end users were allocated or assigned IP address blocks directly, subject only to industry-accepted best practices and Internet community standards. There were no contractual obligations between the registries and these legacy IP address holders.
By the time ARIN appeared on the scene, even as early as 1997, there was concern within the Internet community about possible IPv4 address space exhaustion. To protect against that, ARIN adopted policies designed to discourage IP address hoarding and to promote space reuse. Under ARIN's policy, for example, ISPs that obtain direct allocations of IPv4 addresses require each of their downstream customers to show that it has used at least 80% of its previously assigned IPv4 addresses before receiving any new ones.
Similarly, end users who want to receive additional assignments of IPv4 network space from ARIN must demonstrate that they are using at least 80% of their current addresses, will use at least 25% of the requested addresses immediately and will use 50% of the new addresses within one year of the request, based on reasonable and documented network growth projections.
Failure to comply with ARIN's resource conservation policies could result in the revocation of some of an organization's IPv4 addresses.