IPv6

IPv6 - 128-bit length. The primary change from IPv4 to IPv6 is the length of network addresses. IPv6 addresses are 128 bits long (as defined by RFC 2373 and RFC 2374). IPv6 addresses are typically composed of two logical parts: a 64-bit network prefix, and a 64-bit host part, which is either automatically generated from the interface's MAC address or assigned sequentially. IPv6 - Notation. IPv6 addresses are normally written as eight groups of four hexadecimal digits. For example, 2001:0db8:85a3:08d3:1319:8a2e:0370:73 ...

See also:

IPv6, IPv6 - Features of IPv6, IPv6 - Larger address space, IPv6 - Stateless autoconfiguration of hosts, IPv6 - Multicast, IPv6 - Jumbograms, IPv6 - Faster routing, IPv6 - Network-layer security, IPv6 - Addressing, IPv6 - 128-bit length, IPv6 - Notation, IPv6 - Network notation, IPv6 - Special addresses, IPv6 - IPv6 packet, IPv6 - IPv6 and the Domain Name System, IPv6 - IPv6 deployment, IPv6 - Transition mechanisms, IPv6 - Dual stack, IPv6 - Tunnelling, IPv6 - Proxying and translation, IPv6 - Major IPv6 announcements, IPv6 - Related IETF working groups

Read more here: » IPv6: Encyclopedia II - IPv6 - Addressing

IPv6 - 128-bit length. The primary change from IPv4 to IPv6 is the length of network addresses. IPv6 addresses are 128 bits long (as defined by RFC 2373 and RFC 2374), typically written as 32 hex digits. This gives a total of 2128 or 3.4×1038 addresses, enough to provide an IPv6 /48 network block for every 10 square metres on earth. IPv6 addresses are usually composed of two logical parts: a 64-bit network prefix, and a 64-bit host-addressing part, which is often automatically genera ...

See also:

IPv6, IPv6 - Addressing, IPv6 - 128-bit length, IPv6 - Notation, IPv6 - Network notation, IPv6 - IPv4 addresses in IPv6 format, IPv6 - Special addresses, IPv6 - IPv6 packet, IPv6 - IPv6 and the Domain Name System, IPv6 - IPv6 deployment, IPv6 - Transition mechanisms, IPv6 - Major IPv6 announcements, IPv6 - Related IETF working groups, IPv6 - Links, IPv6 - Misc, IPv6 - Address Space, IPv6 - Software Operating Systems + Applications, IPv6 - IPv6 Task Forces, IPv6 - Relevant News/Reports

Read more here: » IPv6: Encyclopedia II - IPv6 - Addressing

NAT first became popular as a way to deal with the IPv4 address shortage and to avoid the difficulty of reserving IP addresses. Use of NAT has proven particularly popular in countries other than the United States, which (for historical reasons) have fewer address-blocks allocated per capita. It has become a standard feature in routers for home and small-office Internet connections, where the price ...

See also:

Network address translation, Network address translation - Overview, Network address translation - Drawbacks, Network address translation - Benefits, Network address translation - Basic NAT vs port number translation, Network address translation - Applications affected by NAT, Network address translation - Different types of NAT, Network address translation - Other examples of use

Read more here: » Network address translation: Encyclopedia II - Network address translation - Overview

The first header field in an IPv4 packet is the 4-bit version field. The second field is a 4-bit Internet Header Length (IHL) telling the number of 32-bit words in the IPv4 header. Since an IPv4 header may contain a variable number of options, this field essentially specifies the offset to the data portion of an IPv4 datagram. A minimum IPv4 header is 20 bytes long, so the minimum value in decimal in the IHL field would be 5 (5×4 = 20 bytes). That is, it represents the total number of bytes o ...

See also:

IPv4, IPv4 - IPv4 address representations, IPv4 - IPv4 header format, IPv4 - Fragmentation and reassembly

Read more here: » IPv4: Encyclopedia II - IPv4 - IPv4 header format

In computer science and information theory, the issue of error correction and detection has great practical importance. Error detection is the ability to detect errors that are made due to noise or other impairments in the course of the transmission from the transmitter to the receiver. Error correction has the additional feature that enables localization of the errors and correcting them. Error correction schemes permit error localization but also give the possibility of correcting errors that have been introduce ...

Including:

• Error correction and detection - Terminology
• Error correction and detection - Error detection
• Error correction and detection - Typical schemes
• Error correction and detection - Error correction
• Error correction and detection - Applications
• Error correction and detection - The Internet
• Error correction and detection - Deep Space Telecommunications Voyager
• Error correction and detection - Satellite Broadcasting DVB
• Error correction and detection - Information theory and error correction and detection
• Error correction and detection - List of error-detection methods
• Error correction and detection - List of error-correction methods

Read more here: » Error correction and detection: Encyclopedia - Error correction and detection

CGA may stand for: Certified General Accountant Color Graphics Adapter Christian Gamers Alliance Cryptographically Generated Addresses is a method for binding a public signature key to an IPv6 address in the Secure Neighbor Discovery (SEND) protocol. Column Grid Array a large surface mounted electronic component. Category: Ambiguous three-letter acronyms Other related archivesAmbiguous three

Read more here: » CGA: Encyclopedia - CGA

Xerox Palo Alto Research Center (PARC) was a flagship research division of the Xerox Corporation, based in Palo Alto, California, USA. It was founded in 1970, and spun out as a separate company in 2002. It is best known for essentially creating the modern personal computer graphical user interface (GUI) paradigm. Xerox PARC - History. PARC's founding director, George Pake, was an outstanding physicist in the area of nuclear magnetic resonance. Dr. Pake had been serving as provost of Washington University in ...

Including:

• Xerox PARC - History
• Xerox PARC - Accomplishments
• Xerox PARC - Footnote

Read more here: » Xerox PARC: Encyclopedia - Xerox PARC

A Virtual Private Network, or VPN, is a private communications network usually used within a company, or by several different companies or organizations, to communicate over a public network. VPN message traffic is carried on public networking infrastructure (e.g. the Internet) using standard (often insecure) protocols, or over a service provider's network providing VPN service guarded by well defined Service Level Agreement (SLA) between the VPN customer and the VPN service provider. Virtual private network - Aut ...

Including:

• Virtual private network - Authentication mechanism
• Virtual private network - Types of VPNs
• Virtual private network - Characteristics in application
• Virtual private network - Tunneling

Read more here: » Virtual private network: Encyclopedia - Virtual private network

IPv4 addresses are usually written in Dot-decimal notation. Here is an example: 207.142.131.235. But it is also possible to write in the following formats: The above IP addresses should work in most browsers. ...

See also:

IPv4, IPv4 - IPv4 address representations, IPv4 - IPv4 header format, IPv4 - Fragmentation and reassembly

Read more here: » IPv4: Encyclopedia II - IPv4 - IPv4 address representations

A Uniform Resource Identifier (URI), is an Internet protocol element consisting of a short string of characters that conform to a certain syntax. The string comprises a name or address that can be used to refer to a resource. It is a fundamental component of the World Wide Web. Uniform Resource Identifier - Relationship to URL and URN. A URI can be classified as a locator or a name or both. A Uniform Resource Locator (URL) is an URI that, in addition to identifying a resource, provides means of actin ...

Including:

• Uniform Resource Identifier - Relationship to URL and URN
• Uniform Resource Identifier - Syntax
• Uniform Resource Identifier - History
• Uniform Resource Identifier - Naming addressing and identifying resources
• Uniform Resource Identifier - Refinement of specifications
• Uniform Resource Identifier - URI reference
• Uniform Resource Identifier - Uses of URI references in markup languages
• Uniform Resource Identifier - Examples of absolute URIs
• Uniform Resource Identifier - Examples of URI references
• Uniform Resource Identifier - URI resolution
• Uniform Resource Identifier - Relation to XML namespaces

Read more here: » Uniform Resource Identifier: Encyclopedia - Uniform Resource Identifier

Two kinds of network address translation exist. The type often popularly called simply "NAT" (also sometimes named "Network Address Port Translation" or "NAPT") refers to network address translation involving the mapping of port numbers, allowing multiple machines to share a single IP address. The other, technically simpler, form - also called NAT or "basic NAT" or "static NAT" - involves only address translation, not port mapping. This requires an external IP address for each simultaneous connection. Broadband routers often use this feature ...

See also:

Network address translation, Network address translation - Overview, Network address translation - Drawbacks, Network address translation - Benefits, Network address translation - Basic NAT vs port number translation, Network address translation - Applications affected by NAT, Network address translation - Different types of NAT, Network address translation - Other examples of use

Read more here: » Network address translation: Encyclopedia II - Network address translation - Basic NAT vs port number translation

In the fictional .hack world, ALTIMIT OS is virtually the only surviving operating system after the Pluto's Kiss computer virus that destroyed much of the Internet in the mid-2000s. It is also the operating system that is used to play the popular, but fictional, MMORPG The World. Altimit OS was created by Altimit Corporation, with Headoffices in San Francisco, California, USA. ALTIMIT OS - The World. The World, the killer app (most popular application) of Altimit OS, was released in Dec ...

Including:

• ALTIMIT OS - The World
• ALTIMIT OS - Known Features
• ALTIMIT OS - Hardware
• ALTIMIT OS - Remarks

Read more here: » ALTIMIT OS: Encyclopedia - ALTIMIT OS

The year 2025 (MMXXV) in the Gregorian Calendar corresponds to the years 5785/5786 in the Hebrew Calendar. 2025 - Events. Centennial of the Foundation of the Hebrew University of Jerusalem. Predicted year for the start of widespread use of the IPv6 Internet Protocol. Target year for freeing all nations from dictatorships and tyrannies and for establishing worlwide democracy, according to Mark Palmer, in his book Breaking the Real Axis of Evil (2003). Thi ...

Including:

• 2025 - Events

Read more here: » 2025: Encyclopedia - 2025

This list compares various sizes of positive numbers, including counts of things, dimensionless numbers and probabilities. Smaller than 10-36 10-36 10-33 10-30 10-27 10-24 10-21 10-18 10-15 10-12 10-9 10-6 10-3 10-2 10-1 100 101 102 103 104 105 106 109 ...

Including:

• Orders of magnitude numbers - Smaller than 10^-36
• Orders of magnitude numbers - 10^-36
• Orders of magnitude numbers - 10^-33
• Orders of magnitude numbers - 10^-30
• Orders of magnitude numbers - 10^-27
• Orders of magnitude numbers - 10^-24
• Orders of magnitude numbers - 10^-21
• Orders of magnitude numbers - 10^-18
• Orders of magnitude numbers - 10^-15
• Orders of magnitude numbers - 10^-12
• Orders of magnitude numbers - 10^-9
• Orders of magnitude numbers - 10^-6
• Orders of magnitude numbers - 10^-3
• Orders of magnitude numbers - 10^-2
• Orders of magnitude numbers - 10^-1
• Orders of magnitude numbers - 10⁰
• Orders of magnitude numbers - 10¹
• Orders of magnitude numbers - 10²
• Orders of magnitude numbers - 10³
• Orders of magnitude numbers - 10⁴
• Orders of magnitude numbers - 10⁵
• Orders of magnitude numbers - 10⁶
• Orders of magnitude numbers - 10⁹
• Orders of magnitude numbers - 10¹²
• Orders of magnitude numbers - 10¹⁵
• Orders of magnitude numbers - 10¹⁸
• Orders of magnitude numbers - 10²¹
• Orders of magnitude numbers - 10²⁴
• Orders of magnitude numbers - 10²⁷
• Orders of magnitude numbers - 10³⁰
• Orders of magnitude numbers - 10³³
• Orders of magnitude numbers - 10³⁶
• Orders of magnitude numbers - 10³⁸
• Orders of magnitude numbers - Larger than 10³⁹

Read more here: » Orders of magnitude numbers: Encyclopedia - Orders of magnitude numbers

IPv4 supports the use of network elements (e.g. point-point links) which support small packet sizes. Rather than mandate link-local fragmentation and reassembly, which would require the router at the far end of the link to collect the separate pieces and reassemble the packet (a complicated process, especially when pieces may be lost due to errors on the link), a router which discovers that a packet which it is processing is too big to fit on the next link is allowed to break it into fragments (separate IPv4 packets each ...

See also:

IPv4, IPv4 - IPv4 address representations, IPv4 - IPv4 header format, IPv4 - Fragmentation and reassembly

Read more here: » IPv4: Encyclopedia II - IPv4 - Fragmentation and reassembly

BIND (Berkeley Internet Name Domain, previously: Berkeley Internet Name Daemon) is the most commonly used DNS server on the Internet, especially on Unix-like systems, where it is a de facto standard. Supported by Internet Systems Consortium, it was originally created by Paul Vixie in 1988 while working for DEC. A new version of BIND (BIND 9) was written from scratch in part to address the architectural difficulties with auditing the earlier BIND code bases, and also to support DNSSEC (DNS Security Extension ...

Including:

• BIND - Criticisms

Read more here: » BIND: Encyclopedia - BIND

In computer networking and telecommunications, packet switching is the now-dominant communications paradigm, in which packets (units of information carriage) are individually routed between nodes over data links which might be shared by many other nodes. This contrasts with the principal other paradigm, circuit switching, which sets up a dedicated connection between the two nodes for their exclusive use for the duration of the communication. Packet switching is used to optimize the use of the bandwidth available in a network, to minimize the transmission latency (i.e. the time it takes for data to pass across the ...

Including:

• Packet switching - Packets
• Packet switching - Packet routing
• Packet switching - Packet switching in the Internet
• Packet switching - Controversy over invention of packet switching
• Packet switching - Work at MIT
• Packet switching - Work at RAND
• Packet switching - Work at National Physical Laboratory
• Packet switching - Simultaneous Development
• Packet switching - Reference

Read more here: » Packet switching: Encyclopedia - Packet switching

The original IEEE 802 MAC address, now officially called "MAC-48", comes from the Ethernet specification. Since the original designers of Ethernet had the foresight to use a 48-bit address space, there are potentially 248 or 281,474,976,710,656 possible MAC addresses. All three numbering systems use the same format, and differ only in the length of the identifier. The first three octets (in transmission order) identify the organization which issued the identifier, and are known as the Organizationally Unique Identifier (OUI ...

See also:

MAC address, MAC address - Address details, MAC address - Printed format, MAC address - Changing MAC addresses, MAC address - Linux, MAC address - FreeBSD, MAC address - OpenBSD, MAC address - Mac OS X, MAC address - Windows, MAC address - Other systems, MAC address - Change The MAC Address Permanently

Read more here: » MAC address: Encyclopedia II - MAC address - Address details

Apache web server was originally created by Rob McCool, who was heavily involved with the National Center for Supercomputing Applications web server, known simply as NCSA httpd. When Rob left NCSA in mid-1994, the development of httpd stalled, leaving a variety of patches for improvements circulating through e-mails. These patches were put together by a small group of developers, who eventually released "A patchy server", ...

See also:

Apache HTTP Server, Apache HTTP Server - History, Apache HTTP Server - License, Apache HTTP Server - Usage, Apache HTTP Server - Features, Apache HTTP Server - Apache 2

Read more here: » Apache HTTP Server: Encyclopedia II - Apache HTTP Server - History

Error correction and detection - The Internet. In a typical TCP/IP stack, error detection is performed at multiple levels: Each Ethernet frame carries a CRC-32 checksum. The receiver discards frames if their checksums don't match. The IPv4 header contains a header checksum of the contents of the header (excluding the checksum field). Packets with checksums that don't match are discarded. The checksum was omitted from the IPv6 header, because most current link layer protocols have er ...

See also:

Error correction and detection, Error correction and detection - Error correction, Error correction and detection - Applications, Error correction and detection - The Internet, Error correction and detection - Deep Space Telecommunications, Error correction and detection - Satellite Broadcasting DVB, Error correction and detection - Information theory and error correction and detection, Error correction and detection - List of error-correction methods

Read more here: » Error correction and detection: Encyclopedia II - Error correction and detection - Applications