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Routing loop

Routing loop definition

A routing loop is a common problem in computer networks that occurs when data packets get trapped and continuously move around between routers without reaching their intended destination. Routing loops can happen when routers are given inconsistent or incorrect information (e.g., it may not be synchronized across all routers). They cause delays and waste network resources.

See also: data transmission, node, routing table

How a routing loop may form

  • In a computer network, there can be multiple paths or routes that data packets can take to reach their destination.
  • Sometimes, data packets may be given “conflicting directions” because of errors or misconfigurations.
  • Routers exchange information with each other to update their routing tables. They share details about the available paths and the shortest ways of reaching various destinations.
  • If the routing tables contain incorrect information, it can create a loop. For example, Router A might think Router B has the best path, while Router B thinks Router A has the best path. This creates a circular reference.
  • When a data packet is sent from one router to another, it follows the routing table's instructions. However, in a loop, the packet keeps going back and forth between the routers because they keep pointing to each other as the next hop.
  • The data packet gets trapped in this endless circulation between the routers, never reaching its destination. It's like being stuck in a loop where you keep going in circles without getting closer to your destination.

Problems routing loops may cause

  • Data transmission delays
  • Wasted network resources
  • Disrupted network communication
  • Network congestion
  • Increased network load
  • Data loss or corruption