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Supernetwork
A supernetwork, or supernet, is an Internet Protocol (IP) network that is formed by aggregation of multiple networks (or subnets) into a larger network. The new routing prefix for the aggregate network represents the constituent networks in a single routing table entry. The process of forming a supernet is called supernetting, prefix aggregation, route aggregation, or route summarization. Supernetting within the Internet serves as a strategy to avoid fragmentation of the IP address space by using a hierarchical allocation system that delegates control of segments of address space to regional Internet registries. This method facilitates regional route aggregation. The benefits of supernetting are efficiencies gained in routers in terms of memory storage of route information and processing overhead when matching routes. Supernetting, however, can introduce interoperability issues and other risks. Overview In IP networking terminology, a supernet is a block of contiguous subnet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subnetwork
A subnetwork or subnet is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting. Computers that belong to the same subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields: the ''network number'' or ''routing prefix'' and the ''rest field'' or ''host identifier''. The ''rest field'' is an identifier for a specific host or network interface. The ''routing prefix'' may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (''/''), and ending with the bit-length of the prefix. For example, is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range to belon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subnetwork
A subnetwork or subnet is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting. Computers that belong to the same subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields: the ''network number'' or ''routing prefix'' and the ''rest field'' or ''host identifier''. The ''rest field'' is an identifier for a specific host or network interface. The ''routing prefix'' may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (''/''), and ending with the bit-length of the prefix. For example, is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range to belon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Route Aggreation Example-en
Route or routes may refer to: * Route (gridiron football), a path run by a wide receiver * route (command), a program used to configure the routing table * Route, County Antrim, an area in Northern Ireland * ''The Route'', a 2013 Ugandan film * Routes, Seine-Maritime, a commune in Seine-Maritime, France * ''Routes'' (video game), 2003 video game See also * Acronyms and abbreviations in avionics * Air route or airway * GPS route, a series of one or more GPS waypoints * Path (other) * Rout, a disorderly retreat of military units from the field of battle * Route number or road number * Router (other) * Router (woodworking) * Routing (other) * Routing table * Scenic route, a thoroughfare designated as scenic based on the scenery through which it passes * Trade route A trade route is a logistical network identified as a series of pathways and stoppages used for the commercial transport of cargo. The term can also be used to refer to trade over bodies o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classful Addressing
A classful network is an obsolete network addressing architecture used in the Internet from 1981 until the introduction of Classless Inter-Domain Routing (CIDR) in 1993. The method divides the IP address space for Internet Protocol version 4 (IPv4) into five address classes based on the leading four address bits. Classes A, B, and C provide unicast addresses for networks of three different network sizes. Class D is for multicast networking and the class E address range is reserved for future or experimental purposes. Since its discontinuation, remnants of classful network concepts have remained in practice only in limited scope in the default configuration parameters of some network software and hardware components, most notably in the default configuration of subnet masks. Background In the original address definition, the most significant eight bits of the 32-bit IPv4 address was the ''network number'' field which specified the particular network a host was attached to. The re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Terminology
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing. The origins of the Internet date back to the development of packet switching and research commissioned by the United States Department of Defense in the 1960s to enable time-sharing of computers. The primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1970s to enable resource sharing. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Performance
Network performance refers to measures of service quality of a network as seen by the customer. There are many different ways to measure the performance of a network, as each network is different in nature and design. Performance can also be modeled and simulated instead of measured; one example of this is using state transition diagrams to model queuing performance or to use a Network Simulator. Performance measures The following measures are often considered important: * Bandwidth commonly measured in bits/second is the maximum rate that information can be transferred * Throughput is the actual rate that information is transferred * Latency the delay between the sender and the receiver decoding it, this is mainly a function of the signals travel time, and processing time at any nodes the information traverses * Jitter variation in packet delay at the receiver of the information * Error rate the number of corrupted bits expressed as a percentage or fraction of the total sent Ban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Provider-independent Address Space
A provider-independent address space (PI) is a block of IP addresses assigned by a regional Internet registry (RIR) directly to an end-user organization. The user must contract with a local Internet registry (LIR) through an Internet service provider to obtain routing of the address block within the Internet. Provider-independent addresses offer end-users the opportunity to change service providers without renumbering of their networks and to use multiple access providers in a multi-homed configuration. However, provider-independent blocks may increase the burden on global routers, as the opportunity for efficient route aggregation through Classless Inter-Domain Routing (CIDR) may not exist. IPv4 assignments One of the RIRs is RIPE NCC. The RIPE NCC can no longer assign IPv4 Provider Independent (PI) address space as it is now using the last of IPv4 address space that it holds. IPv4 address space from this last is allocated according to section 5.1 of "IPv4 Address Allocation an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Provider-aggregatable Address Space
Provider-aggregatable address space (PA) is a block of IP addresses assigned by a regional Internet registry to an Internet service provider which can be aggregated into a single route advertisement for improved Internet routing efficiency. Unlike provider-independent address space A provider-independent address space (PI) is a block of IP addresses assigned by a regional Internet registry (RIR) directly to an end-user organization. The user must contract with a local Internet registry (LIR) through an Internet service provi ..., the end-user of address blocks within a provider-supplied space cannot reuse the addresses if they change up-stream connectivity providers. References Network addressing IP addresses {{internet-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistent Routing Loop
A routing loop is a common problem with various types of networks, particularly computer networks. They are formed when an error occurs in the operation of the routing algorithm, and as a result, in a group of nodes, the path to a particular destination forms a loop. In the simplest version, a routing loop of size two, node A thinks that the path to some destination (call it C) is through its neighbouring node, node B. At the same time, node B thinks that the path to C starts at node A. Thus, whenever traffic for C arrives at either A or B, it will loop endlessly between A and B, unless some mechanism exists to prevent that behaviour. How a routing loop can form For example, in this illustration, node A is transmitting data to node C via node B. If the link between nodes B and C goes down and B has not yet informed node A about the breakage, node A transmits the data to node B assuming that the link A-B-C is operational and of lowest cost. Node B knows of the broken link and trie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association For Computing Machinery
The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional membership group, claiming nearly 110,000 student and professional members . Its headquarters are in New York City. The ACM is an umbrella organization for academic and scholarly interests in computer science ( informatics). Its motto is "Advancing Computing as a Science & Profession". History In 1947, a notice was sent to various people: On January 10, 1947, at the Symposium on Large-Scale Digital Calculating Machinery at the Harvard computation Laboratory, Professor Samuel H. Caldwell of Massachusetts Institute of Technology spoke of the need for an association of those interested in computing machinery, and of the need for communication between them. ..After making some inquiries during May and June, we believe there is ample interest to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame Relay
Frame Relay is a standardized wide area network (WAN) technology that specifies the physical and data link layers of digital telecommunications channels using a packet switching methodology. Originally designed for transport across Integrated Services Digital Network (ISDN) infrastructure, it may be used today in the context of many other network interfaces. Network providers commonly implement Frame Relay for voice (VoFR) and data as an encapsulation technique used between local area networks (LANs) over a WAN. Each end-user gets a private line (or leased line) to a Frame Relay node. The Frame Relay network handles the transmission over a frequently changing path transparent to all end-user extensively used WAN protocols. It is less expensive than leased lines and that is one reason for its popularity. The extreme simplicity of configuring user equipment in a Frame Relay network offers another reason for Frame Relay's popularity. With the advent of Ethernet over fiber optics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Border Gateway Protocol
Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet. BGP is classified as a path-vector routing protocol, and it makes routing decisions based on paths, network policies, or rule-sets configured by a network administrator. BGP used for routing within an autonomous system is called Interior Border Gateway Protocol, Internal BGP (iBGP). In contrast, the Internet application of the protocol is called Exterior Border Gateway Protocol, External BGP (eBGP). History The Border Gateway Protocol was sketched out in 1989 by engineers on the back of "three ketchup-stained napkins", and is still known as the ''three-napkin protocol''. It was first described in 1989 in RFC 1105, and has been in use on the Internet since 1994. IPv6 BGP was first defined in in 1994, and it was improved to in 1998. The current version of BGP is version 4 (BGP4), which was publishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
