|
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] |
Network 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 va ... [...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] |
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] |
Routing Policy Specification Language
The Routing Policy Specification Language (RPSL) is a language commonly used by Internet Service Providers to describe their routing policies. The routing policies are stored at various whois databases including RIPE, RADB and APNIC. ISPs (using automated tools) then generate router configuration files that match their business and technical policies.RFC2622describes RPSL, and replaced RIPE-181.provides a reference tutorial to using RPSL in practice to support IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv ... routing policies. RPSL Tools and Programs RtConfig- automatically generate router configuration files from RPSL registry entries (This software is part of the IRRToolSet) irrPT- Tools for ISPs to collect and use information from Internet Routing Registry (IRR) databases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Routing Registry
An Internet Routing Registry (IRR) is a database of Internet route objects for determining, and sharing route and related information used for configuring routers, with a view to avoiding problematic issues between Internet service providers. The Internet routing registry works by providing an interlinked hierarchy of objects designed to facilitate the organization of IP routing between organizations, and also to provide data in an appropriate format for automatic programming of routers. Network engineers from participating organizations are authorized to modify the Routing Policy Specification Language (RPSL) objects, in the registry, for their own networks. Then, any network engineer, or member of the public, is able to query the route registry for particular information of interest. Relevant objects * AUT-NUM * INETNUM6 * ROUTE * INETNUM * ROUTE6 * AS-SET Status of implementation In some RIR regions, the adoption/updates of for e.g. AUT-NUM (Represents for e.g. Autonomous sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global BGP Table
In Internet routing, the default-free zone (DFZ) is the collection of all Internet autonomous systems (AS) that do not require a default route to route a packet to any destination. Conceptually, DFZ routers have a "complete" Border Gateway Protocol table, sometimes referred to as the Internet routing table, global routing table or global BGP table. However, internet routing changes rapidly and the widespread use of route filtering ensures that no router has a complete view of all routes. Any routing table created would look different from the perspective of different routers, even if a stable view could be achieved. Highly connected Autonomous Systems and routers The Weekly Routing Reports used by the ISP community come from the Asia-Pacific Network Information Centre (APNIC) router in Tokyo, which is a well-connected router that has as good a view of the Internet as any other single router. For serious routing research, however, routing information will be captured at multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisco Systems
Cisco Systems, Inc., commonly known as Cisco, is an American-based multinational corporation, multinational digital communications technology conglomerate (company), conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, software, telecommunications equipment and other high-technology services and products. Cisco specializes in specific tech markets, such as the Internet of Things (IoT), internet domain, domain security, videoconferencing, and energy management with List of Cisco products, leading products including Webex, OpenDNS, XMPP, Jabber, Duo Security, and Cisco Jasper, Jasper. Cisco is one of the List of largest technology companies by revenue, largest technology companies in the world ranking 74 on the Fortune 100 with over $51 billion in revenue and nearly 80,000 employees. Cisco Systems was founded in December 1984 by Leonard Bosack and Sandy Lerner, two Stanford University computer scientists who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Default-free Zone
In Internet routing, the default-free zone (DFZ) is the collection of all Internet autonomous systems (AS) that do not require a default route to route a packet to any destination. Conceptually, DFZ routers have a "complete" Border Gateway Protocol table, sometimes referred to as the Internet routing table, global routing table or global BGP table. However, internet routing changes rapidly and the widespread use of route filtering ensures that no router has a complete view of all routes. Any routing table created would look different from the perspective of different routers, even if a stable view could be achieved. Highly connected Autonomous Systems and routers The Weekly Routing Reports used by the ISP community come from the Asia-Pacific Network Information Centre (APNIC) router in Tokyo, which is a well-connected router that has as good a view of the Internet as any other single router. For serious routing research, however, routing information will be captured at multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing Assets Database
The Routing Assets Database (RADb), formerly known as the Routing Arbiter Database is a public database in which the operators of Internet networks publish authoritative declarations of routing policy for their Autonomous System (AS) which are, in turn, used by the operators of other Internet networks to configure their inbound routing policy filters. The RADb, operated by the University of Michigan's Merit Network, was the first such database, but others followed in its wake, forming a loose confederation of Internet routing registries, containing sometimes-overlapping, and sometimes-conflicting, routing policy data, expressed in Routing Policy Specification Language (RPSL) syntax. History The RADb was developed in the early 1990s as part of the National Science Foundation (NSF)-funded Routing Arbiter Project. The Routing Policy Specification Language was subsequently retroactively formalized in RFC 2280, in January, 1998. Usage Historically, most larger Internet service ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletraffic Engineering
Teletraffic engineering, telecommunications traffic engineering, or just traffic engineering when in context, is the application of transportation traffic engineering theory to telecommunications. Teletraffic engineers use their knowledge of statistics including queuing theory, the nature of traffic, their practical models, their measurements and simulations to make predictions and to plan telecommunication networks such as a telephone network or the Internet. These tools and knowledge help provide reliable service at lower cost. The field was created by the work of A. K. Erlang for circuit-switched networks but is applicable to packet-switched networks, as they both exhibit Markovian properties, and can hence be modeled by e.g. a Poisson arrival process. The crucial observation in traffic engineering is that in large systems the law of large numbers can be used to make the aggregate properties of a system over a long period of time much more predictable than the behaviour of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
