In
computer networking
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...
, dynamic routing (DR), also called adaptive routing (AR),
is a process where a router can forward data via a different route for a given destination based on the current conditions of the communication circuits within a system. The term is most commonly associated with
data networking to describe the capability of a network to 'route around' damage, such as loss of a node or a connection between nodes, as long as other path choices are available. Dynamic routing allows as many routes as possible to remain valid in response to the change.
Systems that do not implement dynamic routing are described as using
static routing, where routes through a network are described by fixed paths. A change, such as the loss of a node, or loss of a connection between nodes, is not compensated for. This means that anything that wishes to take an affected path will either have to wait for the failure to be repaired before restarting its journey, or will have to fail to reach its destination and give up the journey.
All protocols
There are several
routing protocols that can be used for dynamic routing.
Routing Information Protocol
The Routing Information Protocol (RIP) is one of the oldest distance-vector routing protocols which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from so ...
(RIP) is a
distance-vector routing protocol that prevents
routing loops by implementing a limit on the number of
hops
Hops are the flowers (also called seed cones or strobiles) of the hop plant ''Humulus lupulus'', a member of the Cannabaceae family of flowering plants. They are used primarily as a bittering, flavouring, and stability agent in beer, to whic ...
allowed in a path from source to destination.
Open Shortest Path First
Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single Autonomous syste ...
(OSPF) uses a
link state routing (LSR) algorithm and falls into the group of
interior gateway protocols (IGPs).
[ Intermediate System to Intermediate System (IS-IS) determines the best route for data through a ]packet-switched network
In telecommunications, packet switching is a method of grouping data into short messages in fixed format, i.e. '' packets,'' that are transmitted over a digital network. Packets consist of a header and a payload. Data in the header is used b ...
.[ Interior Gateway Routing Protocol (IGRP) and its advanced form ]Enhanced Interior Gateway Routing Protocol
Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary p ...
(EIGRP) are used by routers to exchange 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 ...
data within an autonomous system.
Alternate paths
Many systems use some next-hop forwarding protocol—when a packet arrives at some node, that node decides on-the-fly which link to use to push the packet one hop closer to its final destination.
Routers that use some adaptive protocols, such as the Spanning Tree Protocol, in order to "avoid bridge loops and routing loops", calculate a tree that indicates the one "best" link for a packet to get to its destination.
Alternate "redundant" links not on the tree are temporarily disabled—until one of the links on the main tree fails, and the routers calculate a new tree using those links to route around the broken link.
Routers that use other adaptive protocols, such as grouped adaptive routing, find a group of ''all'' the links that could be used to get the packet one hop closer to its final destination.
The router sends the packet out any link of that group which is idle.
The link aggregation of that group of links effectively becomes a single high-bandwidth connection.
Outside of computer networks
Dynamic routing in found the brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...
in relation between sensory and mnemonic signals and decision making, and is a subject of studies in neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...
.
See also
* Convergence (routing)
Convergence is the state of a set of routers that have the same topological information about the internetwork in which they operate. For a set of routers to have ''converged'', they must have collected all available topology information from e ...
* InfiniBand
InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency. It is used for data interconnect both among and within computers. InfiniBand is also used ...
* Routing in delay-tolerant networking
References
External links
Session-based routing holds the key to the Internet’s future
{{DEFAULTSORT:Dynamic routing
Routing