Link to home
Start Free TrialLog in
Avatar of BarepAssets
BarepAssetsFlag for Ireland

asked on

EIGRP DUAL Process selecting feasible successor

Hi,.

Can anyone explain to me in eigrp. When a route to a network goes down. Dual searches the topology table for feasible successor.
Why does it not just go to next lowest feasible distance in its topology table. Why does it go through the process of  looking for a route in table with reported distance lower than its current feasible distance ( route  that is gone down)??

thks
ASKER CERTIFIED SOLUTION
Avatar of saurabh_nissh
saurabh_nissh

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of BarepAssets

ASKER

Thanks that is making more sense to me now
Avatar of saurabh_nissh
saurabh_nissh

Advertised Distance (AD) is the total metric along a path to a destination network as advertised by an upstream neighbor.This distance is sometimes also called a Reported Distance and is equal to the current lowest total distance through a successor for a neighboring router.

A Feasible Distance (FD) is the lowest known distance from a router to a particular destination. This is the Advertised Distance (AD) + the cost to reach the neigboring router from which the AD was sent

As FD = AD + cost to reach the neigboring router
So, the shortest the AD, the more preffered the route will be as it minimises the toal cost to the destination.

Hope this clarifies.

Thanks
Nishant