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AS 7007 Incident
The AS 7007 incident was a major disruption of the Internet on April 25, 1997, that started with a router operated by autonomous system 7007 (MAI Network Services, although sometimes incorrectly attributed to the Florida Internet Exchange) accidentally leaking a substantial part of its entire routing table to the Internet, creating a routing black hole. Probably because of a bug in the affected router, the routes leaked were deaggregated to /24 prefixes, which were more specific than the routes originally present on the Internet, and had the AS path rewritten to 7007, leading the Border Gateway Protocol (BGP) used by the Internet's routers to prefer the leaked routes. This was then exacerbated by other problems that prevented the routes from disappearing from other networks' routing tables, even after the original router that had sent them had been disconnected. The combination of these factors resulted in an extended disruption of operations throughout the Internet. Analysis of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
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 shari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Router (computing)
A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions between networks and on the global Internet. Data sent through a network, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork (e.g. the Internet) until it reaches its destination node. A router is connected to two or more data lines from different IP networks. When a data packet comes in on one of the lines, 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. The most familiar type of IP routers are home and small office routers that simply forward IP packets between the home computers and the Internet. More sophisticated routers, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autonomous System (Internet)
An autonomous system (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain, that presents a common and clearly defined routing policy to the Internet. Each AS is assigned an autonomous system number (ASN), for use in Border Gateway Protocol (BGP) routing. Autonomous System Numbers are assigned to Local Internet Registries (LIRs) and end user organizations by their respective Regional Internet Registries (RIRs), which in turn receive blocks of ASNs for reassignment from the Internet Assigned Numbers Authority (IANA). The IANA also maintains a registry of ASNs which are reserved for private use (and should therefore not be announced to the global Internet). Originally, the definition required control by a single entity, typically an Internet service provider (ISP) or a very large organization with independent connections to multiple networks, that adhered to a ... [...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 routing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole (networking)
In networking, a black hole refers to a place in the network where incoming or outgoing traffic is silently discarded (or "dropped"), without informing the source that the data did not reach its intended recipient. When examining the topology of the network, the black holes themselves are invisible, and can only be detected by monitoring the lost traffic; hence the name as astronomical Black holes cannot be directly observed. Dead addresses The most common form of black hole is simply an IP address that specifies a host machine that is not running or an address to which no host has been assigned. Even though TCP/IP provides a means of communicating the delivery failure back to the sender via ICMP, traffic destined for such addresses is often just dropped. Note that a dead address will be undetectable only to protocols that are both connectionless and unreliable (e.g., UDP). Connection-oriented or reliable protocols (TCP, RUDP) will either fail to connect to a dead addr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classless Inter-Domain Routing
Classless Inter-Domain Routing (CIDR ) is a method for allocating IP addresses and for IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous classful network addressing architecture on the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses. IP addresses are described as consisting of two groups of bits in the address: the most significant bits are the network prefix, which identifies a whole network or subnet, and the least significant set forms the ''host identifier'', which specifies a particular interface of a host on that network. This division is used as the basis of traffic routing between IP networks and for address allocation policies. Whereas classful network design for IPv4 sized the network prefix as one or more 8-bit groups, resulting in the blocks of Class A, B, or C addresses, under CIDR address space is allocated to Internet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AS Path
As, AS, A. S., A/S or similar may refer to: Art, entertainment, and media * A. S. Byatt (born 1936), English critic, novelist, poet and short story writer * "As" (song), by Stevie Wonder * , a Spanish sports newspaper * , an academic male voice choir of Helsinki, Finland * Adult Swim, a programming block on Cartoon Network Business legal structures * , a Czech form of joint-stock company * , a Slovak form of joint-stock company * or ''A/S'', a type of Danish stock-based company * or ''AS'', a type of Norwegian stock-based company Businesses and organizations * A.S. Roma, an Italian football club * Alaska Airlines, IATA airline designator * (Belgium), a World War II resistance organization * ''Diario AS'', a Spanish daily sports newspaper that concentrates particularly on football - branded as AS * KK AS Basket, a Serbian basketball club * , a French resistance organization * Oakland Athletics, an American baseball team referred to as the A's * Australian Standards, ... [...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] |
Route Filtering
In the context of network routing, route filtering is the process by which certain routes are not considered for inclusion in the local route database, or not advertised to one's neighbours. Route filtering is particularly important for the Border Gateway Protocol on the global Internet, where it is used for a variety of reasons. One way of doing route filtering with external-resources in practice is using Routing Policy Specification Language in combination with Internet Routing Registry databases. Types of filtering There are two times when a filter can be naturally applied: when learning routes from a neighbour, and when announcing routes to a neighbour. Input filtering In input filtering, a filter is applied to routes as they are learned from a neighbour. A route that has been filtered out is discarded straight away, and hence not considered for inclusion into the local routing database. Output filtering In output filtering, a filter is applied to routes before they are ann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing
Routing is the process of selecting a path for traffic in a 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 to another. Intermediate nodes are typically network hardware devices such as routers, gateways, firewalls, or switches. General-purpose computers also forward packets and perform routing, although they have no specially optimized hardware for the task. The routing process usually directs forwarding on the basis of routing tables. Routing tables maintain a record of the routes to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Architecture
World Wide Web topology is the network topology of the World Wide Web, as seen as a network of web pages connected by hyperlinks. The Jellyfish and Bow Tie models are two attempts at modeling the topology of hyperlinks between web pages. Models of web page topology Jellyfish Model The simplistic Jellyfish model of the World Wide Web centers around a large strongly connected core of high-degree web pages that form a clique; pages such that there is a path from any page within the core to any other page. In other words, starting from any node within the core, it is possible to visit any other node in the core just by clicking hyperlinks. From there, a distinction is made between pages of single degree and those of higher order degree. Pages with many links form rings around the center, with all such pages that are a single link away from the core making up the first ring, all such pages that are two links away from the core making up the second ring, and so on. Then from each ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
