Reserved IP addresses

Last updated

In the Internet addressing architecture, the Internet Engineering Task Force (IETF) and the Internet Assigned Numbers Authority (IANA) have reserved various Internet Protocol (IP) addresses for special purposes. [1]

Contents

IPv4

IPv4 designates special usage or applications for various addresses or address blocks: [1] [2]

Special address blocks
Address blockAddress rangeNumber of addressesScopeDescription
0.0.0.0/80.0.0.0–0.255.255.25516777216SoftwareCurrent (local, "this") network [1]
10.0.0.0/810.0.0.0–10.255.255.25516777216Private networkUsed for local communications within a private network [3]
100.64.0.0/10100.64.0.0–100.127.255.2554194304Private network Shared address space [4] for communications between a service provider and its subscribers when using a carrier-grade NAT
127.0.0.0/8127.0.0.0–127.255.255.25516777216HostUsed for loopback addresses to the local host [1]
169.254.0.0/16169.254.0.0–169.254.255.25565536SubnetUsed for link-local addresses [5] between two hosts on a single link when no IP address is otherwise specified, such as would have normally been retrieved from a DHCP server
172.16.0.0/12172.16.0.0–172.31.255.2551048576Private networkUsed for local communications within a private network [3]
192.0.0.0/24192.0.0.0–192.0.0.255256Private networkIETF Protocol Assignments, DS-Lite (/29) [1]
192.0.2.0/24192.0.2.0–192.0.2.255256DocumentationAssigned as TEST-NET-1, documentation and examples [6]
192.88.99.0/24192.88.99.0–192.88.99.255256InternetReserved. [7] Formerly used for IPv6 to IPv4 relay [8] (included IPv6 address block 2002::/16).
192.168.0.0/16192.168.0.0–192.168.255.25565536Private networkUsed for local communications within a private network [3]
198.18.0.0/15198.18.0.0–198.19.255.255131072Private networkUsed for benchmark testing of inter-network communications between two separate subnets [9]
198.51.100.0/24198.51.100.0–198.51.100.255256DocumentationAssigned as TEST-NET-2, documentation and examples [6]
203.0.113.0/24203.0.113.0–203.0.113.255256DocumentationAssigned as TEST-NET-3, documentation and examples [6]
224.0.0.0/4224.0.0.0–239.255.255.255268435456InternetIn use for multicast [10] (former Class D network)
233.252.0.0/24233.252.0.0–233.252.0.255256DocumentationAssigned as MCAST-TEST-NET, documentation and examples (Note that this is part of the above multicast space.) [10] [11]
240.0.0.0/4240.0.0.0–255.255.255.254268435455InternetReserved for future use [12] (former Class E network)
255.255.255.255/32255.255.255.2551SubnetReserved for the "limited broadcast" destination address [1]

IPv6

IPv6 assigns special uses or applications for various IP addresses: [1]

Special address blocks
Address block (CIDR)First addressLast addressNumber of addressesUsagePurpose
::/128::::1SoftwareUnspecified address
::1/128::1::11Host Loopback address—a virtual interface that loops all traffic back to itself, the local host
::ffff:0:0/96::ffff:0.0.0.0::ffff:0:0::ffff:255.255.255.255::ffff:ffff:ffff232SoftwareIPv4-mapped addresses
::ffff:0:0:0/96::ffff:0:0.0.0.0::ffff:0:0:0::ffff:0:255.255.255.255::ffff:0:ffff:ffff232SoftwareIPv4-translated addresses
64:ff9b::/9664:ff9b::0.0.0.064:ff9b::0:064:ff9b::255.255.255.25564:ff9b::ffff:ffff232The global InternetIPv4/IPv6 translation [13]
64:ff9b:1::/4864:ff9b:1::64:ff9b:1:ffff:ffff:ffff:ffff:ffff280, with 248 for each IPv4Private internetsIPv4/IPv6 translation [14]
100::/64100::100::ffff:ffff:ffff:ffff264RoutingDiscard prefix [15]
2001::/322001::2001:0:ffff:ffff:ffff:ffff:ffff:ffff296The global Internet Teredo tunneling [16]
2001:20::/282001:20::2001:2f:ffff:ffff:ffff:ffff:ffff:ffff2100Software ORCHIDv2 [17]
2001:db8::/322001:db8::2001:db8:ffff:ffff:ffff:ffff:ffff:ffff296DocumentationAddresses used in documentation and example source code [18]
2002::/162002::2002:ffff:ffff:ffff:ffff:ffff:ffff:ffff2112The global InternetThe 6to4 addressing scheme (deprecated) [7]
3fff::/203fff::3fff:fff:ffff:ffff:ffff:ffff:ffff:ffff2108DocumentationAddresses used in documentation and example source code [19]
5f00::/165f00::5f00:ffff:ffff:ffff:ffff:ffff:ffff:ffff2112RoutingIPv6 Segment Routing (SRv6) [20]
fc00::/7fc00::fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff2121Private internets Unique local address [21]
fe80::/64 from fe80::/10fe80::fe80::ffff:ffff:ffff:ffff264Link Link-local address
ff00::/8ff00::ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff2120The global Internet Multicast address

See also

Related Research Articles

An Internet Protocol address is a numerical label such as 192.0.2.1 that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface identification, and location addressing.

<span class="mw-page-title-main">IPv4</span> Fourth version of the Internet Protocol

Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was the first version deployed for production on SATNET in 1982 and on the ARPANET in January 1983. It is still used to route most Internet traffic today, even with the ongoing deployment of Internet Protocol version 6 (IPv6), its successor.

<span class="mw-page-title-main">IPv6</span> Version 6 of the Internet Protocol

Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion, and was intended to replace IPv4. In December 1998, IPv6 became a Draft Standard for the IETF, which subsequently ratified it as an Internet Standard on 14 July 2017.

A multicast address is a logical identifier for a group of hosts in a computer network that are available to process datagrams or frames intended to be multicast for a designated network service. Multicast addressing can be used in the link layer, such as Ethernet multicast, and at the internet layer for Internet Protocol Version 4 (IPv4) or Version 6 (IPv6) multicast.

Bogon filtering is the practice of filtering bogons, which are bogus (fake) IP addresses of a computer network. Bogons include IP packets on the public Internet that contain addresses that are not in any range allocated or delegated by the Internet Assigned Numbers Authority (IANA) or a delegated regional Internet registry (RIR) and allowed for public Internet use. The areas of unallocated address space are called the bogon space.

In computer networking, localhost is a hostname that refers to the current computer used to access it. The name localhost is reserved for loopback purposes. It is used to access the network services that are running on the host via the loopback network interface. Using the loopback interface bypasses any local network interface hardware.

In Internet networking, a private network is a computer network that uses a private address space of IP addresses. These addresses are commonly used for local area networks (LANs) in residential, office, and enterprise environments. Both the IPv4 and the IPv6 specifications define private IP address ranges.

example.com Domain name reserved for documentation purposes and as an example of the use of domain names

The domain names example.com, example.net, example.org, and example.edu are second-level domain names in the Domain Name System of the Internet. They are reserved by the Internet Assigned Numbers Authority (IANA) at the direction of the Internet Engineering Task Force (IETF) as special-use domain names for documentation purposes. The domain names are used widely in books, tutorials, sample network configurations, and generally as examples for the use of domain names. The Internet Corporation for Assigned Names and Numbers (ICANN) operates websites for these domains with content that reflects their purpose.

The name example is reserved by the Internet Engineering Task Force (IETF) as a domain name that may not be installed as a top-level domain in the Domain Name System (DNS) of the Internet.

The name localhost is reserved by the Internet Engineering Task Force (IETF) as a domain name label that may not be installed as a top-level domain in the Domain Name System (DNS) of the Internet.

<span class="mw-page-title-main">Brian Carpenter (engineer)</span> British internet engineer

Brian Edward Carpenter is a British Internet engineer and a former chair of the Internet Engineering Task Force (IETF), the Internet Architecture Board (IAB), and the Internet Society.

In computer networking, a link-local address is a network address that is valid only for communications on a local link, i.e. within a subnetwork that a host is connected to. Link-local addresses are typically assigned automatically through a process known as link-local address autoconfiguration, also known as auto-IP, automatic private IP addressing, and stateless address autoconfiguration. While most link-local addresses are unicast, this is not necessarily the case; e.g. IPv6 addresses beginning with ff02:, and IPv4 addresses beginning with 224.0.0. are multicast addresses that are link-local.

An IPv6 transition mechanism is a technology that facilitates the transitioning of the Internet from the Internet Protocol version 4 (IPv4) infrastructure in use since 1983 to the successor addressing and routing system of Internet Protocol Version 6 (IPv6). As IPv4 and IPv6 networks are not directly interoperable, transition technologies are designed to permit hosts on either network type to communicate with any other host.

A unique local address (ULA) is an Internet Protocol version 6 (IPv6) address in the address range fc00::/7. These addresses are non-globally reachable. For this reason, ULAs are somewhat analogous to IPv4 private network addressing, but with significant differences. Unique local addresses may be used freely, without centralized registration, inside a single site or organization or spanning a limited number of sites or organizations.

The Internet Protocol Version 4 address 0.0.0.0 can have multiple uses.

<span class="mw-page-title-main">IPv6 address</span> Label to identify a network interface of a computer or other network node

An Internet Protocol version 6 address is a numeric label that is used to identify and locate a network interface of a computer or a network node participating in a computer network using IPv6. IP addresses are included in the packet header to indicate the source and the destination of each packet. The IP address of the destination is used to make decisions about routing IP packets to other networks.

An IPv6 packet is the smallest message entity exchanged using Internet Protocol version 6 (IPv6). Packets consist of control information for addressing and routing and a payload of user data. The control information in IPv6 packets is subdivided into a mandatory fixed header and optional extension headers. The payload of an IPv6 packet is typically a datagram or segment of the higher-level transport layer protocol, but may be data for an internet layer or link layer instead.

NAT64 is an IPv6 transition mechanism that facilitates communication between IPv6 and IPv4 hosts by using a form of network address translation (NAT). The NAT64 gateway is a translator between IPv4 and IPv6 protocols, for which function it needs at least one IPv4 address and an IPv6 network segment comprising a 32-bit address space. The "well-known prefix" reserved for this service is 64:ff9b::/96.

In order to ensure proper working of carrier-grade NAT (CGN), and, by doing so, alleviating the demand for the last remaining IPv4 addresses, a /10 size IPv4 address block was assigned by Internet Assigned Numbers Authority (IANA) to be used as shared address space. This block of addresses is specifically meant to be used by Internet service providers that implement carrier-grade NAT, to connect their customer-premises equipment (CPE) to their core routers.

References

  1. 1 2 3 4 5 6 7 M. Cotton; L. Vegoda; B. Haberman (April 2013). R. Bonica (ed.). Special-Purpose IP Address Registries. IETF. doi: 10.17487/RFC6890 . ISSN   2070-1721. BCP 153. RFC 6890.Best Common Practice. Obsoletes RFC  4773, 5156, 5735 and 5736. Updated by RFC  8190.
  2. ↑ "IANA IPv4 Special-Purpose Address Registry". IANA . 19 August 2009.
  3. 1 2 3 Y. Rekhter; B. Moskowitz; D. Karrenberg; G. J. de Groot; E. Lear (February 1996). Address Allocation for Private Internets. Network Working Group. doi: 10.17487/RFC1918 . BCP 5. RFC 1918.Best Common Practice. Obsoletes RFC  1627 and 1597. Updated by RFC  6761.
  4. ↑ J. Weil; V. Kuarsingh; C. Donley; C. Liljenstolpe; M. Azinger (April 2012). IANA-Reserved IPv4 Prefix for Shared Address Space. Internet Engineering Task Force. doi: 10.17487/RFC6598 . ISSN   2070-1721. BCP 153. RFC 6598.Best Common Practice. Updates RFC  5735.
  5. ↑ S. Cheshire; B. Aboba; E. Guttman (May 2005). Dynamic Configuration of IPv4 Link-Local Addresses. Network Working Group. doi: 10.17487/RFC3927 . RFC 3927.Proposed Standard.
  6. 1 2 3 J. Arkko; M. Cotton; L. Vegoda (January 2010). IPv4 Address Blocks Reserved for Documentation. Internet Engineering Task Force. doi: 10.17487/RFC5737 . ISSN   2070-1721. RFC 5737.Informational. Updates RFC  1166.
  7. 1 2 O. Troan (May 2015). B. Carpenter (ed.). Deprecating the Anycast Prefix for 6to4 Relay Routers. Internet Engineering Task Force. doi: 10.17487/RFC7526 . BCP 196. RFC 7526.Best Current Practice. Obsoletes RFC  3068 and 6732.
  8. ↑ C. Huitema (June 2001). An Anycast Prefix for 6to4 Relay Routers. Network Working Group. doi: 10.17487/RFC3068 . RFC 3068.Informational. Obsoleted by RFC  7526.
  9. ↑ S. Bradner; J. McQuaid (March 1999). Benchmarking Methodology for Network Interconnect Devices. Network Working Group. doi: 10.17487/RFC2544 . RFC 2544.Informational. Updated by: RFC  6201 and RFC  6815.
  10. 1 2 M. Cotton; L. Vegoda; D. Meyer (March 2010). IANA Guidelines for IPv4 Multicast Address Assignments. IETF. doi: 10.17487/RFC5771 . ISSN   2070-1721. BCP 51. RFC 5771.Best Common Practice. Obsoletes RFC  3138 and 3171. Updates RFC  2780.
  11. ↑ S. Venaas; R. Parekh; G. Van de Velde; T. Chown; M. Eubanks (August 2012). Multicast Addresses for Documentation. Internet Engineering Task Force. doi: 10.17487/RFC6676 . ISSN   2070-1721. RFC 6676.Informational.
  12. ↑ J. Reynolds, ed. (January 2002). Assigned Numbers: RFC 1700 is Replaced by an On-line Database. Network Working Group. doi: 10.17487/RFC3232 . RFC 3232.Informational. Obsoletes RFC  1700.
  13. ↑ C. Bao; C. Huitema; M. Bagnulo; M. Boucadair; X. Li (October 2010). IPv6 Addressing of IPv4/IPv6 Translators. Internet Engineering Task Force (IETF). doi: 10.17487/RFC6052 . ISSN   2070-1721. RFC 6052.Proposed Standard. Updates RFC  4291.
  14. ↑ T. Anderson (August 2017). Local-Use IPv4/IPv6 Translation Prefix. Internet Engineering Task Force. doi: 10.17487/RFC8215 . RFC 8215.Proposed Standard.
  15. ↑ N. Hilliard; D. Freedman (August 2012). A Discard Prefix for IPv6. Internet Engineering Task Force. doi: 10.17487/RFC6666 . ISSN   2070-1721. RFC 6666.Informational.
  16. ↑ S. Santesson (September 2006). TLS Handshake Message for Supplemental Data. Network Working Group. doi: 10.17487/RFC4680 . RFC 4680.Proposed Standard. Updates RFC  4346. Updated by RFC  8447 and 8996.
  17. ↑ J. Laganier; F. Dupont (September 2014). An IPv6 Prefix for Overlay Routable Cryptographic Hash Identifiers Version 2 (ORCHIDv2). Internet Engineering Task Force. doi: 10.17487/RFC7343 . ISSN   2070-1721. RFC 7343.Proposed Standard. Obsoletes RFC  4843.
  18. ↑ G. Huston; A. Lord; P. Smith (July 2004). IPv6 Address Prefix Reserved for Documentation. Network Working Group. doi: 10.17487/RFC3849 . RFC 3849.Informational.
  19. ↑ G. Huston; N. Buraglio (August 2024). Expanding the IPv6 Documentation Space. Internet Engineering Task Force (IETF). doi: 10.17487/RFC9637 . RFC 9637.Informational. Updates RFC  3849.
  20. ↑ Krishnan, S. (2024-02-15). SRv6 Segment Identifiers in the IPv6 Addressing Architecture. IETF. I-D draft-ietf-6man-sids-06. Retrieved 2024-06-13.
  21. ↑ R. Hinden; B. Haberman (October 2005). Unique Local IPv6 Unicast Addresses. Network Working Group. doi: 10.17487/RFC4193 . RFC 4193.Proposed Standard.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.