Instruct: Given a question, retrieve documents that answer the question.
Query: Are IP addresses based on location?
Advertisers may also deliver ads based on a user's suspected geography through geotargeting. A user's IP address communicates some geographic information (at minimum, the user's country or general region). The geographic information from an IP can be supplemented and refined with other proxies or information to narrow the range of possible locations. For example, with mobile devices, advertisers can sometimes use a phone's GPS receiver or the location of nearby mobile towers. Cookies and other persistent data on a user's machine may provide help narrowing a user's location further.
Today, these two versions of the Internet Protocol are in simultaneous use. Among other technical changes, each version defines the format of addresses differently. Because of the historical prevalence of IPv4, the generic term "IP address" typically still refers to the addresses defined by IPv4. The gap in version sequence between IPv4 and IPv6 resulted from the assignment of version 5 to the experimental Internet Stream Protocol in 1979, which however was never referred to as IPv5.
Stemming from the first specifications of TCP in 1974, TCP/IP emerged in mid-late 1978 in nearly its final form, as used for the first decades of the Internet, known as "IPv4". which is described in IETF publication RFC 791 (September 1981).
IPv4 uses 32-bit addresses which limits the address space to 2 addresses, i.e. addresses. The last available IPv4 address was assigned in January 2011. IPv4 is being replaced by its successor, called "IPv6", which uses 128 bit addresses, providing 2 addresses, i.e. . This is a vastly increased address space. The shift to IPv6 is expected to take many years, decades, or perhaps longer, to complete, since there were four billion machines with IPv4 when the shift began.
An IP address conflict occurs when two devices on the same local physical or wireless network claim to have the same IP address. A second assignment of an address generally stops the IP functionality of one or both of the devices. Many modern operating systems notify the administrator of IP address conflicts. If one of the devices is the gateway, the network will be crippled. When IP addresses are assigned by multiple people and systems with differing methods, any of them may be at fault.
Classful network design allowed for a larger number of individual network assignments and fine-grained subnetwork design. The first three bits of the most significant octet of an IP address were defined as the "class" of the address. Three classes ("A", "B", and "C") were defined for universal unicast addressing. Depending on the class derived, the network identification was based on octet boundary segments of the entire address. Each class used successively additional octets in the network identifier, thus reducing the possible number of hosts in the higher order classes ("B" and "C"). The following table gives an overview of this now obsolete system.
IP address spoofing is most frequently used in denial-of-service attacks, where the objective is to flood the target with an overwhelming volume of traffic, and the attacker does not care about receiving responses to the attack packets. Packets with spoofed IP addresses are more difficult to filter since each spoofed packet appears to come from a different address, and they hide the true source of the attack. Denial of service attacks that use spoofing typically randomly choose addresses from the entire IP address space, though more sophisticated spoofing mechanisms might avoid unroutable addresses or unused portions of the IP address space. The proliferation of large botnets makes spoofing less important in denial of service attacks, but attackers typically have spoofing available as a tool, if they want to use it, so defenses against denial-of-service attacks that rely on the validity of the source IP address in attack packets might have trouble with spoofed packets. Backscatter, a technique used to observe denial-of-service attack activity in the Internet, relies on attackers' use of IP spoofing for its effectiveness.
Masks are used with IP addresses in IP ACLs (Access Control Lists) to specify what should be permitted and denied. To configure IP addresses on interfaces, masks start with 255 and have the large values on the left side: for example, IP address 209.165.202.129 with a 255.255.255.224 mask. Masks for IP ACLs are the reverse: for example, mask 0.0.0.255. This is sometimes called an inverse mask or a wildcard mask. When the value of the mask is broken down into binary (0s and 1s), the results determine which address bits are to be considered in processing the traffic. A 0 indicates that the address bits must be considered (exact match); a 1 in the mask is a "don't care". This table further explains the concept.
IP stacks need to correlate Ethernet addresses (MAC address) and IP addresses, using a specific protocol named ARP. When a RTP-MIDI application wants to send a packet to a remote device, it must locate it first on the network, since Ethernet does not understand IP-related concepts, in order to create the transmission path between the routers/switches. This is done automatically by the IP stack by sending first an ARP (Address Recognition Protocol) request. When the destination device recognizes its own IP address in the ARP packet, it sends back an ARP reply with its MAC address. The IP stack can then send the RTP-MIDI packet. The next RTP-MIDI packets do not need the ARP sequence anymore, unless the link becomes inactive for a few minutes, which clears the ARP entry in the sender's routing table.
"Charging function addresses" are addresses distributed to each IMS entities and provide a common location for each entity to send charging information. "charging data function" (CDF) addresses are used for offline billing and "Online Charging Function" (OCF) for online billing.IMS-based PES (PSTN Emulation System) provides IP networks services to analog devices. IMS-based PES allows non-IMS devices to appear to IMS as normal SIP users. Analog terminal using standard analog interfaces can connect to IMS-based PES in two ways:
The first specification of IP tunneling was in RFC 1075, which described DVMRP, the first IP multicast routing protocol. Because multicast used special IPv4 addresses, testing DVMRP required a way to get IP datagrams across portions of the Internet that did not yet recognize multicast addresses. This was solved by IP tunneling. The first approach to IP tunneling used an IP Loose Source Route and Record (LSRR) Option to hide the multicast address from the non-multicast aware routers. A multicast-aware destination router would remove the LSRR option from the packet and restore the multicast IP address to the packet's IP destination field. The other approach in the DVMRP specification was IP in IP, as described above. IP in IP soon became the preferred approach, and was later put to use in the Mbone.
Classful network design served its purpose in the startup stage of the Internet, but it lacked scalability in the face of the rapid expansion of networking in the 1990s. The class system of the address space was replaced with Classless Inter-Domain Routing (CIDR) in 1993. CIDR is based on variable-length subnet masking (VLSM) to allow allocation and routing based on arbitrary-length prefixes. Today, remnants of classful network concepts function only in a limited scope as the default configuration parameters of some network software and hardware components (e.g. netmask), and in the technical jargon used in network administrators' discussions.
IPv4 multicast packets are delivered using the Ethernet MAC address range 01:00:5e:00:00:00–01:00:5e:7f:ff:ff (with an OUI owned by the IANA). This range has 23 bits of available address space. The first octet (01) includes the broadcast/multicast bit. The lower 23 bits of the 28-bit multicast IP address are mapped into the 23 bits of available Ethernet address space. This means that there is ambiguity in delivering packets. If two hosts on the same subnet each subscribe to a different multicast group whose address differs only in the first 5 bits, Ethernet packets for both multicast groups will be delivered to both hosts, requiring the network software in the hosts to discard the unrequired packets.
Hosts
A substantial portion of Silicon Valley is located on the peninsula. In Silicon Valley are the headquarters of some of the largest tech companies in the world, such as Google, Yahoo, Facebook and Apple. Over the last decade or so there has been an influx of immigration into the Bay Area from places like India and China to work in the technology industry. There are well over 6,600 tech startups in the Valley and new ones are created every day.
No formal specification of this textual IP address representation exists. The first mention of this format in RFC documents was in RFC 780 for the Mail Transfer Protocol published May 1981, in which the IP address was supposed to be enclosed in brackets or represented as a 32bit decimal integer prefixed by a pound sign. A table in RFC 790 ("Assigned Numbers") used the dotted decimal format, zero-padding each number to three digits. RFC 1123 ("Requirements for Internet Hosts – Application and Support") from October 1989 mentions a requirement on host software to accept “IP address in dotted-decimal ("#.#.#.#") form”, although it notes “[t]his last requirement is not intended to specify the complete syntactic form for entering a dotted-decimal host number”. A separate IETF draft to define textual representation of IP addresses expired.
In August 2007, a tool called WikiScanner—developed by Virgil Griffith, a visiting researcher from the Santa Fe Institute in New Mexico—was released to match edits to the encyclopedia by non-registered users with an extensive database of IP addresses. News stories appeared about IP addresses from various organizations such as the Central Intelligence Agency, the National Republican Congressional Committee, the Democratic Congressional Campaign Committee, Diebold, Inc. and the Australian government being used to make edits to Wikipedia articles, sometimes of an opinionated or questionable nature. Another story stated that an IP address from the BBC itself had been used to vandalize the article on George W. Bush. The BBC quoted a Wikipedia spokesperson as praising the tool: "We really value transparency and the scanner really takes this to another level. Wikipedia Scanner may prevent an organisation or individuals from editing articles that they're really not supposed to." Not everyone hailed WikiScanner as a success for Wikipedia. Oliver Kamm, in a column for "The Times", argued instead that:
Ivan Pope (1961-) is a British technologist who was involved with a number of early internet developments in the UK and across the world, and invented the "cybercafe" at London's Institute of Contemporary Arts. He was a founder of two of the first internet magazines, The World Wide Web Newsletter, and later .net magazine in the UK. In 1994 he founded Webmedia to professionalise the process of web site design and build. In 1995 he was involved with the creation of the domain name management company NetNames. Pope is now a writer and a noted proponent of the dérive.
Web navigation came about with the introduction of the World Wide Web, in 1989 when Timothy Berners-Lee invented it. Once the world wide web was available, web navigation increasingly became a major aspect and role in jobs and everyday lives. With one-third of the world’s population now using the internet, web navigation maintains a global use in today's ever evolving international society. Web navigation is not restricted to just computers, either, as mobile phones and tablets have added avenues for access to the ever-growing information on the web today. The most recent wave of technology which has affected web navigation is the introduction and growth of the smartphone. As of January 2014, 58% of American adults owned a smart phone, and that number is on the rise from previous years. Web navigation has evolved from a restricted action, to something that many people across the world now do on a daily basis.
Geocoder (Ruby) is a geocoding library for Ruby. Geocoding helps to enhance webpages by presenting location relevant information to the user. When used with Rails, Geocoder adds geocoding functionality such as finding coordinates with street addresses or vice versa in addition to distance calculations for ActiveRecord objects. Since the functionality does not rely on proprietary database functions, finding different geocoded objects in an area works out-of-the-box for databases like MySQL, PostgreSQL and SQLite.
There are 70 primary Interstate Highways in the Interstate Highway System, a network of controlled-access freeways in the United States. They are assigned one- or two-digit route numbers, whereas their associated "auxiliary" Interstate Highways receive three-digit route numbers. Typically, odd-numbered Interstates run south-north, with lower numbers in the west and higher numbers in the east; even-numbered Interstates run west-east, with lower numbers in the south and higher numbers in the north. Highways whose route numbers are divisible by "5" usually represent major coast-to-coast or border-to-border routes (ex. I-10 travels from Santa Monica, California, to Jacksonville, Florida, traveling from the Pacific to Atlantic oceans). Additionally, auxiliary highways have their numbering system where a different number prefixes the number of its parent highway.
Another feature offered by some smart thermostats through the internet connection is geofencing. A geofence is a perimeter boundary created around the location of a smartphone or other device, based on GPS signals. The benefit of having a smart thermostat with geofencing capabilities is that it uses a users smartphone location to determine whether the home is occupied. Instead of using a schedule or sensor to determine occupancy, the smart thermostat can rely on the location of the geofence to tell the HVAC system whether it needs to be on or off. Since most people carry their phones with them, geofencing can be an accurate way to determine occupancy patterns.
IP communication provides for device mobility. For example, a residential broadband connection may be used as a link to a virtual private network of a corporate entity, in which case the IP address being used for customer communications may belong to the enterprise, not being the IP address of the residential ISP. Such off-premises extensions may appear as part of an upstream IP PBX. On mobile devices, e.g., a 3G handset or USB wireless broadband adapter, the IP address has no relationship with any physical location known to the telephony service provider, since a mobile user could be anywhere in a region with network coverage, even roaming via another cellular company.
The design and operation of the Internet is based on the Internet Protocol Suite, commonly also called TCP/IP.
IP is the primary protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering datagrams from the source host to the destination host solely based on their addresses. For this purpose, IP defines addressing methods and structures for datagram encapsulation. It is a connectionless protocol and relies on the transmission of packets. Every IP packet from a given source has an ID that uniquely identifies IP datagram.
Neustar IP Intelligence, formerly named Quova, is a company that identifies the geographical location of website visitors based on IP addresses. The company is based in Mountain View, California and is a wholly owned subsidiary of Neustar, Inc. The company's CEO is Lisa Hook. Customers include Major League Baseball, which uses the service to black out MLB.tv content in a team's home area.
The configuration of a static IP address depends in detail on the software or hardware installed in the computer. Computers used for the network infrastructure, such as routers and mail servers, are typically configured with static addressing, Static addresses are also sometimes convenient for locating servers inside an enterprise.