Cybertelecom Federal Internet Law & Policy An Educational Project

IP Numbers

A defining characteristic of being on a network is utilization of the network’s address space. On the Internet, the address space is Internet Protocol Numbers. IP numbers are assigned to each Internet host (i.e., computer). The entire collection of IP numbers is managed by the Internet Assigned Number Authority (IANA) under the authority of ICANN. IANA then delegates large blocks of numbers and assignment responsibilities to Regional Internet Registries (RIRs):

• American Registry of Internet Numbers (ARIN),
• Asia Pacific Network Information Center (APNic),
• Réseaux IP Européens Network Coordination Centre, (RIPE NCC)
• Latin American and Caribbean IP address Regional Registry (Lacnic), and
• AfriNIC.

The RIRs then delegate large blocks of numbers to large networks such as Internet backbones, universities, or large corporate networks. Smaller networks or end users get IP numbers from their upstream network providers.

Example:

• Joe gets his IP number for his computer from ACME ISP.
• ACME ISP gets its backbone connection and IP number block from BETA Backbone.
• Beta Backbone gets its number delegation from ARIN.
• ARIN gets its numbers from IANA.

A packet of data going through the Internet is addressed with the IP number of its destination. The routers through which the packet is transmitted look only at the address (have no regard for the content of the packet) and routes the packet using routing tables determining the best available route. To be visible, a device must be associated with an address; if a device is not associated with an address, it cannot be reached and is not “on network.”

Now consider that although devices on network are reachable using IP numbers, those numbers are largely known only to the network. Humans are all but unaware of IP numbers. Instead, recognizing years ago that the IP numbers are difficult for the humans to remember, the domain name system (DNS) was developed. A domain name is an alias for an IP number, that is both easier to remember and also can be reassigned from one IP number (one computer at one host) to another IP number (another computer at another host) without any interruption of service.

Partly out of a belief that the IPv4 set of available numbers is limited and becoming exhausted, IPv6 has been developed and is being deployed.

Derived From: GAO, Internet Protocol version 6, Federal Agencies Need to Plan for Transition and Manage Security Risks (May 2005)

As originally designed, the first 8 bits of a 32 bit IPv4 address identified the network, and the remaining 24 bits were the address on the local network. This added up to a system that would accomodate 256 networks. Well, in 1978, it occurred to some engineers that there might be more than 256 networks that might want to interconnect to the Internet. Therefore, a system known as "classful addressing" was developed. In this system, IP numbers would be distributed in blocks as follows:

• Class A: the high-order bit is zero, the next 7 bits are the network, and the last 24 bits are the local address;
• Class B: the high-order 2 bits are one-zero, the next 14 bits are the network, and the last 16 bits are the local address; and
• Class C: the high-order 3 bits are one-one-zero, the next 21 bits are the network, and the last 8 bits are the local address.

[Karrenberg, Development of RIRs]

IPv4 Address Conservation

Networks seek to conserve IPv4 Addresses through the following techniques:

• The use of Network Address Translation devices (NATs) which allow whole networks to be placed behind single IP addresses
• CIDR
• Reclaiming unused IPv4 address space

See IPv6 Number Migration.

IANA

• IANA.  See also ICANN.
• RFC 2860, Memorandum of Understanding Concerning the Technical Work of the Internet Assigned Numbers Authority (June 2000)
• D -- Operation of the Internet Assigned Numbers Authority (IANA) functions.Presolicitation Notice Jan 28 2003
• NTIA: IANA Documents

Numbering Assignments

It was said that some US universities have more IPv4 numbers than some countries.

• "Stanford University , which was originally allocated nearly 17 million IP addresses , restructured its network in 2000 and gave back a Class A address block equal to approximately 16 million IP addresses. See Carolyn Marsan, “Stanford Move Rekindles ‘Net Address Debate,’” NWFusion (Jan. 24, 2000), http://www.nwfusion.com/news/2000/0124ipv4.html." NTIA Report: Technical and Economic Assessment of IPv6, p. 12 n 47 July 2004
• Ripe NCC, “Global Distribution of IP-Addresses,”.

Papers

• IPv4 WHOIS Map, CAIDA 10/10/2007
• Development of the RIRs, IP Journal (Dec. 2001)
• S. Romano, M Stahl, RFC 1020, Internet Numbers (Nov. 1997) ("The responsibility for the assignment of IP numbers and ASNs has been assumed by Hostmaster at the DDN Network Information Center (NIC). The Hostmaster staff are indebted to Dr. Jon Postel and Ms. Joyce Reynolds of the Information Sciences Institute at the University of Southern California for their ongoing assistance.")
• 3COM:  Understanding IP Addressing:  Everything You Ever Wanted to Know PDF
• Daniel Karrenberg, RIPE-NCC; Gerard Ross, APNIC; Paul Wilson, APNIC; Leslie Nobile, ARIN, Development of the Regional Internet Registry System (December 2001)
• IETF
  • IETF RFC 2050: Goals and Guidelines of RIRs
  • Postel, J., "Assigned Numbers," RFC 790, September 1981
  • RFC 791, Internet Protocol: DARPA Internet Program Protocol Specification , (Sept 1981) ("This document specifies the DoD Standard Internet Protocol. This document is based on six earlier editions of the ARPA Internet Protocol Specification, and the present text draws heavily from them.")  
  • RFC 760, DOD Standard: Internet Protocol (Jan. 1980) ("This document specifies the DoD Standard Internet Protocol.")

Webcasts

• How Prevalent is Prefix HiJakcing on the Internet, NANOG Feb. 2006 (attributing significant number of misconfigs to fat-fingers).
• Regional Internet Registries Statistics and Activities, NANOG 3/26/2004

Links

• RIRs
  • American Registry of Internet Numbers (ARIN <www.arin.net>),
  • Asia Pacific Network Information Center (APNic <www.apnic.net>),
  • RIPE Network Coordination Centre <www.ripe.net>,
  • Latin American and Caribbean IP address Regional Registry (Lacnic <www.lacnic.net>), and
  • AfriNIC <www.afrinic.net>.
    • PanAfrica: Africa's Own Net Registry On Track, AllAfrica 6/1/200
• IANA
  • IPv4 Address Space Allocations
  • IPv6 Top Level Aggregation Identifier Assignments
  • ASNs Autonomous System Numbers
• Geoff Huston :: IPv4 Report :: IPv6 Report ::
• USG :: NIST :: CSD :: IPSec Project

Liability Based on IP Numbers

• Your computer on the Internet has an Internet address, an IP number. Everything that is done on your computer leaves that IP number like a bread crumb trail across the Internet. If you visit a site, you IP number is left in the server log, and anyone looking at that log can see that IP number. That IP number belongs to a block of IP numbers assigned to your ISP. In order to trace that IP number back to you, the RIAA and other groups use DMCA to subpoena ISPs for the subscriber information associated with that IP number. What is provided to the RIAA is the name of the individual who subscribed to the ISP; not necessarily the person who visited that Internet site. In the case of home Internet accounts that have open WiFi access points attached to them, the person who visited the site in question can be anyone who wandered in range of the WiFi signal and piggy backed on the account. Even those who have secured Internet access at home, the person who visited the site in question could be any friend, guest, or relative that happened to visit that house and used that computer. Defendants having open WiFi access points have successfully used the arguement that an IP number is not a human being and is not proof that the account owner did the bad deed; it could have been anyone who piggy backed onto the network. In a few other cases, cases have been improperly filed where the plaintiffs had the IP number misidentified. Nevertheless, a number of copyright litigations and criminal charges have been brought simply based on the identification of an IP number.

  • RIAA Attacks Open Wi-Fi Hotspots - Wants ISP account holder liable for all activity via Wi-Fi, Broadband Reports 2/23/2007
• See P2P Litigations :: WiFi AP Liability ::

News & Blogs

• IP Address Allocation vs. Internet Production I: Understanding the Relationship, and the Differences, CircleID 4/29/2005
• The Geography of Internet Addressing, CircleID 4/27/2005