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.
23-429: Washington K-20 Network is a wide area network providing educational Internet access in the U.S. state of Washington for schools and educational service districts , colleges and community colleges, and libraries. The network was formed in 1996. A state settlement with Qwest Communications funded network access to state libraries starting in 2000–2001. WWAMI medical schools began to participate in 2007. The network
46-429: A network bridge are also on the same link, whereas hosts on different sides of a network router are on different links. In IPv4 , the utility of link-local addresses is in zero-configuration networking when Dynamic Host Configuration Protocol (DHCP) services are not available and manual configuration by a network administrator is not desirable. The block 169.254.0.0 / 16 was allocated for this purpose. If
69-414: A WAN is a computer network spanning regions, countries, or even the world. However, in terms of the application of communication protocols and concepts, it may be best to view WANs as computer networking technologies used to transmit data over long distances, and between different networks. This distinction stems from the fact that common local area network (LAN) technologies operating at lower layers of
92-428: A host on an IEEE 802 ( Ethernet ) network cannot obtain a network address via DHCP, an address from 169.254.1.0 to 169.254.254.255 may be assigned pseudorandomly . The standard prescribes that address collisions must be handled gracefully. In IPv6 , the block fe80:: / 10 is reserved for IP address autoconfiguration. The implementation of these link-local addresses is mandatory, as various functions of
115-585: A new laser that potentially quadruples transfer speeds with fiber optics. Private network Most Internet service providers (ISPs) allocate only a single publicly routable IPv4 address to each residential customer, but many homes have more than one computer , smartphone , or other Internet-connected device. In this situation, a network address translator (NAT/PAT) gateway is usually used to provide Internet connectivity to multiple hosts. Private addresses are also commonly used in corporate networks which, for security reasons, are not connected directly to
138-500: A private IP address cannot be routed through the public Internet. Private addresses are often seen as enhancing network security for the internal network since use of private addresses internally makes it difficult for an external host to initiate a connection to an internal system. The Internet Engineering Task Force (IETF) has directed the Internet Assigned Numbers Authority (IANA) to reserve
161-468: A single operator's points of presence in a large metropolitan area such as Tokyo . The concept of private networks has been extended in the next generation of the Internet Protocol , IPv6 , and special address blocks are reserved. The address block fc00:: / 7 is reserved by IANA for unique local addresses (ULAs). They are unicast addresses, but contain a 40-bit random number in
184-562: A spoofed source address. Less commonly, ISP edge routers drop such egress traffic from customers, which reduces the impact to the Internet of such misconfigured or malicious hosts on the customer's network. Since the private IPv4 address space is relatively small, many private IPv4 networks unavoidably use the same address ranges. This can create a problem when merging such networks, as some addresses may be duplicated for multiple devices. In this case, networks or hosts must be renumbered, often
207-421: A time-consuming task or a network address translator must be placed between the networks to translate or masquerade one of the address ranges. IPv6 defines unique local addresses , providing a very large private address space from which each organization can randomly or pseudo-randomly allocate a 40-bit prefix, each of which allows 65536 organizational subnets. With space for about one trillion (10 ) prefixes, it
230-409: The fec0:: / 10 block, but because of scalability concerns and poor definition of what constitutes a site , its use has been deprecated since September 2004. Another type of private networking uses the link-local address range. The validity of link-local addresses is limited to a single link; e.g. to all computers connected to a switch , or to one wireless network . Hosts on different sides of
253-516: The Internet . Often a proxy , SOCKS gateway, or similar devices are used to provide restricted Internet access to network-internal users. Private network addresses are not allocated to any specific organization. Anyone may use these addresses without approval from regional or local Internet registries . Private IP address spaces were originally defined to assist in delaying IPv4 address exhaustion . IP packets originating from or addressed to
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#1732802335306276-594: The OSI model (such as the forms of Ethernet or Wi-Fi ) are often designed for physically proximal networks, and thus cannot transmit data over tens, hundreds, or even thousands of miles or kilometres. WANs are used to connect LANs and other types of networks together so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers , provide connections from an organization's LAN to
299-501: The IPv6 protocol depend on them. A special case of private link-local addresses is the loopback interface . These addresses are private and link-local by definition since packets never leave the host device. IPv4 reserves the entire class A address block 127.0.0.0 / 8 for use as private loopback addresses. IPv6 reserves the single address ::1 . It is common for packets originating in private address spaces to be misrouted onto
322-665: The Internet. WANs are often built using leased lines . At each end of the leased line, a router connects the LAN on one side with a second router within the LAN on the other. Because leased lines can be very expensive, instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH , Multiprotocol Label Switching (MPLS), Asynchronous Transfer Mode (ATM) and Frame Relay are often used by service providers to deliver
345-605: The Internet. Private networks often do not properly configure DNS services for addresses used internally and attempt reverse DNS lookups for these addresses, causing extra traffic to the Internet root nameservers . The AS112 project attempted to mitigate this load by providing special black hole anycast nameservers for private address ranges which only return negative result codes ( not found ) for these queries. Organizational edge routers are usually configured to drop ingress IP traffic for these networks, which can occur either by misconfiguration or from malicious traffic using
368-481: The following IPv4 address ranges for private networks: In practice, it is common to subdivide these ranges into smaller subnets . In April 2012, IANA allocated the 100.64.0.0 / 10 block of IPv4 addresses specifically for use in carrier-grade NAT scenarios. This address block should not be used on private networks or on the public Internet. The size of the address block was selected to be large enough to uniquely number all customer access devices for all of
391-647: The links that are used in WANs. It is also possible to build a WAN with Ethernet . Academic research into wide area networks can be broken down into three areas: mathematical models , network emulation , and network simulation . Performance improvements are sometimes delivered via wide area file services or WAN optimization . Of the approximately four billion addresses defined in IPv4, about 18 million addresses in three ranges are reserved for use in private networks . Packets addressed in these ranges are not routable on
414-419: The private addresses, for transmission across the public network. Additionally, encapsulated packets may be encrypted to secure their data. Many technologies are available for wide area network links. Examples include circuit-switched telephone lines, radio wave transmission, and optical fiber . New developments have successively increased transmission rates. In c. 1960 , a 110 bit/s line
437-509: The public Internet; they are ignored by all public routers. Therefore, private hosts cannot directly communicate with public networks, but require network address translation at a routing gateway for this purpose. Since two private networks, e.g., two branch offices, cannot directly communicate via the public Internet, the two networks must be bridged across the Internet via a virtual private network (VPN) or other form of IP tunnel that encapsulates packets, including their headers containing
460-462: The routing prefix to prevent collisions when two private networks are interconnected. Despite being inherently local in usage, the IPv6 address scope of unique local addresses is global. The first block defined is fd00:: / 8 , designed for / 48 routing blocks, in which users can create multiple subnets, as needed. Examples: A former standard proposed the use of site-local addresses in
483-403: The world. In essence, this mode of telecommunication allows a business to effectively carry out its daily function regardless of location. The Internet may be considered a WAN. Many WANs are, however, built for one particular organization and are private. WANs can be separated from local area networks (LANs) in that the latter refers to physically proximal networks. The textbook definition of
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#1732802335306506-682: Was connected to Internet2 via Pacific Northwest Gigapop in 2001. As of 2013, the network had over 475 nodes, including almost 450 schools and colleges, and 30 libraries or library systems. This Washington -related article is a stub . You can help Misplaced Pages by expanding it . Wide area network A wide area network ( WAN ) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits . Businesses, as well as schools and government entities, use wide area networks to relay data to staff, students, clients, buyers and suppliers from various locations around
529-941: Was normal on the edge of the WAN, while core links of 56 or 64 kbit/s were considered fast. Today, households are connected to the Internet with dial-up , asymmetric digital subscriber line (ADSL), cable , WiMAX , cellular network or fiber . The speeds that people can currently use range from 28.8 kbit/s through a 28K modem over a telephone connection to speeds as high as 100 Gbit/s using 100 Gigabit Ethernet . The following communication and networking technologies have been used to implement WANs. AT&T conducted trials in 2017 for business use of 400-gigabit Ethernet . Researchers Robert Maher, Alex Alvarado, Domaniç Lavery, and Polina Bayvel of University College London were able to increase networking speeds to 1.125 terabits per second. Christos Santis, graduate student Scott Steger, Amnon Yariv, Martin and Eileen Summerfield developed
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