0.0.0.0

Last updated

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

Contents

Uses

Official meaning and use

IANA, who allocate IP addresses globally, have allocated the single IP address 0.0.0.0 [1] to RFC   1122 section 3.2.1.3. It is named as "This host on this network".

RFC 1122 refers to 0.0.0.0 using the notation {0,0}. It prohibits this as a destination address in IPv4 and only allows it as a source address under specific circumstances.

A host may use 0.0.0.0 as its own source address in IP when it has not yet been assigned an address, such as when sending the initial DHCPDISCOVER packet when using DHCP.

Operating system specific uses

Some operating systems have attributed special internal meanings to the address. These uses do not result in IPv4 packets containing 0.0.0.0 and so are not governed by RFC 1122. [2] These meanings may not be consistent between OS.

In both Windows and Linux, when selecting which of a host's IP address to use as a source IP, a program may specify INADDR_ANY (0.0.0.0). [3] [4]

In Linux a program may specify 0.0.0.0 as the remote address to connect to the current host (AKA localhost). [2]

Other non-standard uses

Besides the use by operating systems internally, other uses have been attributed to the address. [5] [6]

Routing

In routing tables, 0.0.0.0 can also appear in the gateway column. This indicates that the gateway to reach the corresponding destination subnet is unspecified. This generally means that no intermediate routing hops are necessary because the system is directly connected to the destination. [9]

The CIDR notation 0.0.0.0/0 defines an IP block containing all possible IP addresses. It is commonly used in routing to depict the default route as a destination subnet. It matches all addresses in the IPv4 address space and is present on most hosts, directed towards a local router.

In IPv6

In IPv6, the all-zeros address is typically represented by :: (two colons), which is the short notation of 0000:0000:0000:0000:0000:0000:0000:0000. [10] The IPv6 variant serves the same purpose as its IPv4 counterpart.

See also

Related Research Articles

The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks for automatically assigning IP addresses and other communication parameters to devices connected to the network using a client–server architecture.

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.

The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when communicating with another IP address. For example, an error is indicated when a requested service is not available or that a host or router could not be reached. ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems, nor is it regularly employed by end-user network applications.

<span class="mw-page-title-main">Internet Protocol version 4</span> Fourth version of the Internet Protocol

Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). 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.

In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages to other hosts on an Internet Protocol (IP) network. Within an IP network, UDP does not require prior communication to set up communication channels or data paths.

Classless Inter-Domain Routing is a method for allocating IP addresses for IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous classful network addressing architecture on the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses.

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.

The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. ARP was defined in 1982 by RFC 826, which is Internet Standard STD 37.

<span class="mw-page-title-main">Subnet</span> Logical subdivision of an IP network

A subnetwork, or subnet, is a logical subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.

Zero-configuration networking (zeroconf) is a set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manual operator intervention or special configuration servers. Without zeroconf, a network administrator must set up network services, such as Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS), or configure each computer's network settings manually.

A broadcast address is a network address used to transmit to all devices connected to a multiple-access communications network. A message sent to a broadcast address may be received by all network-attached hosts.

A Martian packet is an IP packet seen on the public Internet that contains a source or destination address that is reserved for special use by the Internet Assigned Numbers Authority (IANA) as defined in RFC 1812, Appendix B Glossary. On the public Internet, such a packet either has a spoofed source address, and it cannot actually originate as claimed, or the packet cannot be delivered. The requirement to filter these packets is found in RFC 1812, Section 5.3.7.

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.

The Neighbor Discovery Protocol (NDP), or simply Neighbor Discovery (ND), is a protocol of the Internet protocol suite used with Internet Protocol Version 6 (IPv6). It operates at the internet layer of the Internet model, and is responsible for gathering various information required for network communication, including the configuration of local connections and the domain name servers and gateways.

The Dynamic Host Configuration Protocol version 6 (DHCPv6) is a network protocol for configuring Internet Protocol version 6 (IPv6) hosts with IP addresses, IP prefixes, default route, local segment MTU, and other configuration data required to operate in an IPv6 network. It is not just the IPv6 equivalent of the Dynamic Host Configuration Protocol for IPv4.

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 most often unicast network addresses assigned automatically through a process known as stateless address autoconfiguration (SLAAC) or link-local address autoconfiguration, also known as automatic private IP addressing (APIPA) or auto-IP. Link-local addresses are not all unicast; 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.

<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.

References

  1. ↑ "IANA IPv4 Special-Purpose Address Registry". Internet Assigned Numbers Authority. 19 August 2009. Retrieved 7 June 2023.
  2. 1 2 Kitt, Stephen (26 January 2018). "Connecting to IP 0.0.0.0 succeeds. How? Why?". Stack Exchange . Retrieved 7 June 2023.
  3. ↑ Kerrisk, Michael (22 March 2021). "ip(7) — Linux manual page". man7.org. Retrieved 7 June 2023.
  4. ↑ "bind function (winsock.h) - Win32 apps". Microsoft Learn . 19 August 2022. Retrieved 7 June 2023.
  5. ↑ Postill, David (2 August 2015). "What's the difference between 127.0.0.1 and 0.0.0.0?". Stack Exchange. Retrieved 7 June 2023.
  6. ↑ Mitchell, Bradley (16 December 2018). "What It Means When You See the 0.0.0.0 IP Address". Lifewire . Retrieved 7 June 2023.
  7. ↑ R. Woundy; K. Marez (December 2006). Cable Device Management Information Base for Data-Over-Cable Service Interface Specification (DOCSIS) Compliant Cable Modems and Cable Modem Termination Systems. Network Working Group. doi: 10.17487/RFC4639 . RFC 4639.Proposed Standard. p. 32. Obsoletes RFC  2669 . Updated by RFC  9141 . If 0.0.0.0, either syslog transmission is inhibited, or the Syslog server address is not an IPv4 address.
  8. ↑ Kitt, Stephen (19 November 2022). "Why accessing 0.0.0.0:443 gets redirected to 127.0.0.1:443 on Linux and how to disallow it?". Stack Exchange. Retrieved 7 June 2023.
  9. ↑ Henry-Stocker, Sandra (4 August 2013). "Unix: Getting from here to there (routing basics)". Network World . Retrieved 7 June 2023.
  10. ↑ Das, Kaushik (2008). "IPv6 Addressing". ipv6.com. Archived from the original on 11 April 2015. Retrieved 7 June 2023.
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.