Instruct: Given a question, retrieve passages that answer the question.
Query: What does IP stand for in IP address?
An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.
An IP address serves two principal functions: host or network interface identification and location addressing.
The most prominent component of the Internet model is the Internet Protocol (IP), which provides addressing systems, including IP addresses, for computers on the network. IP enables internetworking and, in essence, establishes the Internet itself. Internet Protocol Version 4 (IPv4) is the initial version used on the first generation of the Internet and is still in dominant use. It was designed to address up to ≈4.3 billion (10) hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion, which entered its final stage in 2011, when the global address allocation pool was exhausted. A new protocol version, IPv6, was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 is currently in growing deployment around the world, since Internet address registries (RIRs) began to urge all resource managers to plan rapid adoption and conversion.
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.
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.
Some online locators determine user location from the user's IP address, rather than asking a user to input his or her location. The company utilizes IP geolocation software from Digital Element to power the “My Local Ace” section of its website. Based on a site visitor’s location, the website can show the visitor how many stores are in their area, as well as a city-level locator map to help the customer find the store closest to their address.
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.
The Mobile IP allows for location-independent routing of IP datagrams on the Internet. Each mobile node is identified by its home address disregarding its current location in the Internet. While away from its home network, a mobile node is associated with a "care-of" address which identifies its current location and its home address is associated with the local endpoint of a tunnel to its "home agent". Mobile IP specifies how a mobile node registers with its home agent and how the home agent routes datagrams to the mobile node through the "tunnel".
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.
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.
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.
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.
Hosts
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.
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.
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.
"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:
Group D
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.
Group C
The Sun 1,447,959 -7%
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.
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.
An IP address serves two principal functions. It identifies the host, or more specifically its network interface, and it provides the location of the host in the network, and thus the capability of establishing a path to that host. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."
The header of each IP packet contains the IP address of the sending host, and that of the destination host.
An IP address is a unique numerical label assigned to a computer connected to a computer network that uses the Internet Protocol for communication. The most popular implementation of the Internet Protocol would be the Internet (capitalized, to differentiate it from smaller internetworks). Internet Service Providers (ISPs) are allocated chunks of IP addresses by a Regional Internet registry, which they then assign to customers. However, ISPs do not have enough addresses to give the customers their own address. Instead, DHCP is used; a customer's device (typically a modem or router) is assigned an IP address from a pool of available addresses. It keeps that address for a certain amount of time (e.g., two weeks). If the device is still active at the end of the lease, it can renew its connection and keep the same IP address. Otherwise, the IP address is collected and added to the pool to be redistributed. Thus, IP addresses provide regional information (through Regional Internet registries) and, if the ISP has logs, specific customer information. While this does not prove that a specific person was the originator of a blog post (it could have been someone else using that customer's Internet, after all), it provides powerful circumstantial evidence.
For security and privacy considerations, network administrators often desire to restrict public Internet traffic within their private networks. The source and destination IP addresses contained in the headers of each IP packet are a convenient means to discriminate traffic by IP address blocking or by selectively tailoring responses to external requests to internal servers. This is achieved with firewall software running on the networks gateway router. A database of IP addresses of permissible traffic may be maintained in blacklists or whitelists.