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Subnet Mask
A subnet, or subnetwork, 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 group of its most-significant bits of 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 as the first address of a network, written in Classless Inter-Domain Routing (CIDR) notation, 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 rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stateless Address Autoconfiguration
An Internet Protocol version 6 address (IPv6 address) is a numeric label that is used to identify and locate a network interface of a computer or a network node participating in a computer network using IPv6. IP addresses are included in the packet header to indicate the source and the destination of each packet. The IP address of the destination is used to make decisions about routing IP packets to other networks. IPv6 is the successor to the first addressing infrastructure of the Internet, Internet Protocol version 4 (IPv4). In contrast to IPv4, which defined an IP address as a 32-bit value, IPv6 addresses have a size of 128 bits. Therefore, in comparison, IPv6 has a vastly enlarged address space. Addressing methods IPv6 addresses are classified by the primary addressing and routing methodologies common in networking: unicast addressing, anycast addressing, and multicast addressing. A unicast address identifies a single network interface. The Internet Protocol delivers pac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ones' Complement
The ones' complement of a binary number is the value obtained by inverting (flipping) all the bits in the Binary number, binary representation of the number. The name "ones' complement" refers to the fact that such an inverted value, if added to the original, would always produce an "all ones" number (the term "Method of complements, complement" refers to such pairs of mutually additive inverse numbers, here in respect to a non-0 base number). This mathematical operation is primarily of interest in computer science, where it has varying effects depending on how a specific computer represents numbers. A ones' complement system or ones' complement arithmetic is a system in which negative numbers are represented by the inverse of the binary representations of their corresponding positive numbers. In such a system, a number is negated (converted from positive to negative or vice versa) by computing its ones' complement. An N-bit ones' complement numeral system can only represent int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 subnetw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Table
In computer networking, a routing table, or routing information base (RIB), is a data table stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes. The routing table contains information about the topology of the network immediately around it. The construction of routing tables is the primary goal of routing protocols. Static routes are entries that are fixed, rather than resulting from routing protocols and network topology discovery procedures. Overview A routing table is analogous to a distribution map in package delivery. Whenever a node needs to send data to another node on a network, it must first know ''where'' to send it. If the node cannot directly connect to the destination node, it has to send it via other nodes along a route to the destination node. Each node needs to keep track of which way to deliver various packages of data, and for this it uses a ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link-local Address
In computer networking, a link-local address is a network address that is valid only for communications on a ''local link'', i.e. within a subnetwork that a host is connected to. Link-local addresses are typically assigned automatically through a process known as link-local address autoconfiguration, also known as auto-IP, automatic private IP addressing (APIPA, specific to IPv4), and stateless address autoconfiguration (SLAAC, specific to IPv6). While most link-local addresses are unicast, this is not necessarily the case; e.g. IPv6 addresses beginning with (), and IPv4 addresses beginning with () are multicast addresses that are link-local. Link-local addresses are not guaranteed to be unique beyond their network segment. Therefore, routers do not forward packets with link-local source or destination addresses. IPv4 link-local unicast addresses are assigned from address block ( through ). In IPv6, unicast link-local addresses are assigned from the block . Address assi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neighbor Discovery Protocol
The Neighbor Discovery Protocol (NDP), or simply Neighbor Discovery (ND), is a protocol of the Internet protocol suite used with Internet Protocol Version 6 (IPv6). It operates at the internet layer of the Internet model, and is responsible for gathering various information required for network communication, including the configuration of local connections and the domain name servers and gateways. The protocol defines five ICMPv6 packet types to perform functions for IPv6 similar to the Address Resolution Protocol (ARP) and Internet Control Message Protocol (ICMP) ICMP Router Discovery Protocol, Router Discovery and ICMP Redirect Message, Router Redirect protocols for IPv4. It provides many improvements over its IPv4 counterparts. For example, it includes Neighbor Unreachability Detection (NUD), thus improving robustness of packet delivery in the presence of failing routers or links, or mobile nodes. The Inverse Neighbor Discovery (IND) protocol extension allows nodes to deter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classful Network
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Switch
A network switch (also called switching hub, bridging hub, Ethernet switch, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device. A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model. Some switches can also forward data at the network layer (layer 3) by additionally incorporating routing functionality. Such switches are commonly known as layer-3 switches or multilayer switches. Switches for Ethernet are the most common form of network switch. The first MAC Bridge was invented in 1983 by Mark Kempf, an engineer in the Networking Advanced Development group of Digital Equipment Corporation. The first 2 port Bridge product (LANBridge 100) was introduced by that company shortly after. The company subsequently produced multi-port switches for both Ethernet and FDDI such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethernet
Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET. The original 10BASE5 Ethernet uses a thick coaxial cable as a shared medium. This was largely superseded by 10BASE2, which used a thinner and more flexible cable that was both less expensive and easier to use. More modern Ethernet variants use Ethernet over twisted pair, twisted pair and fiber optic links in conjunction with Network switch, switches. Over the course of its history, Ethernet data transfer rates have been increased from the original to the lates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Router (computing)
A router is a computer and networking device that Packet forwarding, forwards data packets between computer networks, including internetworks such as the global Internet. Routers perform the "traffic directing" functions on the Internet. A router is connected to two or more data lines from different IP networks. When a data packet comes in on a line, the router reads the network address information in the packet header to determine the ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey. Data packets are forwarded from one router to another through an internetwork until it reaches its destination Node (networking), node. The most familiar type of Internet Protocol, IP routers are Residential gateway, home and small office routers that forward IP packet (other), IP packets between the home computers and the Internet. More sophisticated routers, such as enterprise routers, conne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing
Routing is the process of selecting a path for traffic in a Network theory, network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network (PSTN), and computer networks, such as the Internet. In packet switching networks, routing is the higher-level decision making that directs network packets from their source toward their destination through intermediate network nodes by specific packet forwarding mechanisms. Packet forwarding is the transit of network packets from one Network interface controller, network interface to another. Intermediate nodes are typically network hardware devices such as Router (computing), routers, gateway (telecommunications), gateways, Firewall (computing), firewalls, or network switch, switches. General-purpose computers also forward packets and perform routing, although they have no specially optimized hardware for the task. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
