IP address fight in N.J. worries ISPs

Computerworld - A New Jersey State Court ruling in a case involving the use of Internet Protocol addresses by a Web hosting firm is causing alarm among some network operators who believe it may create a dangerous precedent.
University Communications Inc., a Parsipanny. N.J.-based Web hosting company, earlier this week secured a temporary restraining order (download PDF) that allows it to continue using its current IP addresses -- even after terminating its contract with the assigning service provider.
The court ruling temporarily prevents UCI's current service provider, Net Access Corp. (NAC), from interfering in any way with UCI's use of the IP addresses assigned to it by NAC, even after UCI has signed up with another provider.
The American Registry for Internet Numbers (ARIN), which reviewed the case, said many of the concerns about it may have resulted from the way in which the litigation was described by one of the parties. The organization plans to monitor the case as it develops, according to ARIN's president and CEO, Ray Plzak. But ARIN, in a statement, said it has no plans for now to intervene.
An IP address is the set of numbers associated with a Web site on the Internet. These numbers are used by the Internet's routing system to direct traffic to and from Web sites. In North America, the numbers are assigned by ARIN, typically to large ISPs, which in turn reallocate them to their customers. Some large companies have their own range of IP numbers.
Typically, if a customer is assigned IP address space by a provider, the ISP gets the addresses back when the customer leaves. Allowing UIC to retain the use of its IP numbers after it has discontinued its relationship with NAC will create a "very dangerous" precedent, said NAC President Alex Rubenstein in a letter posted on the North American Network Operators Group mailing list,

"If this ruling is upheld it has the potential to disrupt routing throughout the Internet, and change practices of business for any Internet Service Provider," he wrote in the post. That note has led to quite a bit of discussion on the NANOG mailing list over the past two days.
Allowing people to carry their IP numbers even when switching providers will put an additional layer of routing complexity on an already overburdened system, said Paul Mockapetris, inventor of the Internet's Domain Name System. "The problem is that there is no present capability to support IP address portability in the routers of the network," he said.
"The forefront technical issue