Etäisyysvektoriprotokolla

Etäisyysvektoriprotokolla, often abbreviated as DV protocol, is a routing protocol used in computer networks. It operates by having each router maintain a table of distances (or "costs") to all other known destinations in the network. This distance is typically represented by a hop count, where each router a packet passes through increments the count.

The core principle of DV protocols is that each router periodically exchanges its entire routing table with its immediate neighbors. When a router receives an updated routing table from a neighbor, it compares the advertised distances with its own current distances. If the neighbor offers a shorter path to a particular destination, the router updates its own routing table with this new, more efficient route.

A key characteristic of DV protocols is their susceptibility to routing loops. A routing loop occurs when a packet is forwarded indefinitely between two or more routers without ever reaching its intended destination. This can happen due to temporary network changes or faulty updates. To mitigate this, DV protocols often employ mechanisms such as split horizon, poison reverse, and hop count limits to detect and break loops.

Examples of distance-vector routing protocols include RIP (Routing Information Protocol) and IGRP (Interior Gateway Routing Protocol). While historically significant, many DV protocols have been superseded by link-state routing protocols like OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System) in modern, larger networks due to their greater scalability and faster convergence times. DV protocols are generally simpler to implement and understand, making them suitable for smaller, less complex network environments.