EIGRP Distance Vector Route Discovery

April 27, 2014

EIGRP’s route discovery process uses a “routing by rumour” approach. Meaning that the routers in an autonomous system heard about their routes from another autonomous system/router, they did not receive the route information first hand.This essentially means the routers heard about the routes by listening to network gossip.

The information collected is stored in the following tables.

  • Neighbour Table
  • Topology Table
  • Router Table

With this EIGRP will calculate the best paths and any redundant links (if available) using the following:

  • Bandwidth
  • Delay
  • Load
  • Reliability

MTU is sometimes reffered to being used but it in fact is not, it is only used for some commands but doesn’t affect the outcome of the formula.