How many feasible successors are there in EIGRP?

We can tell from this output that there is only one successor route, through R5 (with a feasible distance of 3072), but the secondary route through R4 is being held as a feasible successor.

How many feasible successors are stored in a topology table?

A feasible successor is a path whose reported distance is less than the feasible distance, and it is considered a backup route. EIGRP will keep up to six feasible successors in the topology table. Only the one with the best metric (the successor) is placed in the routing table.

What is the benefit of having a feasible successor route with EIGRP?

EIGRP maintains redundant routes in memory so that if one fails, reverting to an backup route can occur instantaneously. A feasible successor is a backup route that can be used in the event of a topology change without having to recalculate routes.

How do you find the feasible successor in EIGRP?

These backup routes are stored in the topology table. For a route to be chosen as a feasible successor, one condition must be met: the neighbor’s advertised distance (AD) for the route must be less than the successor’s feasible distance (FD).

What is feasible condition in EIGRP?

The Feasibility Condition states that a route will not be accepted if the Reported Distance is more than the best path’s Feasible Distance. Or said another way and from the perspective of the router: a path to a network will not be accepted if my neighbor’s cost is more than my cost.

Where are EIGRP successor routes stored in?

Successor routes are saved in the topology table to be used if the primary route fails. Successor routes are flagged as “active” in the routing table. A successor route may be backed up by a feasible successor route. Successor routes are stored in the neighbor table following the discovery process.

What will an EIGRP router do if the successor route fails and there is no feasible successor?

A router has EIGRP configured as the only routing protocol. How does EIGRP respond if there is no feasible successor route to a destination network and the successor route fails? A. It immediately sends its entire routing table to its neighbors.

What is the formula for selecting a feasible successor?

In order for a route to become a feasible successor, the following condition must be met: the neighbor’s advertised distance (AD) for the route must be less than the successor’s feasible distance (FD).

Which EIGRP table displays successor and feasible successor routes?

Explanation: Successor routes are going to be in the routing table since they are the best path to a remote network. However, the topology table has a link to each and every network, so the best answer is topology table and routing table.

Which command will display all the EIGRP feasible successor routes known in a router?

Solution(By Examveda Team) Any secondary route to a remote network is considered a feasible successor, and those routes are only found in the topology table and used as backup routes in case of primary route failure. You can see the topology table with the show ip eigrp topology command.

What is a feasible successor route in EIGRP?

A route is entered into the EIGRP topology table as a feasible successor only if it meets the feasibility condition, which asserts that the reported distance of a route must be lower than the feasible distance of the current successor route. To better illustrate this concept, consider the following scenario.

Can EIGRP maintain less-than-optimal routes?

However, under certain conditions, EIGRP will also maintain less-than-optimal routes in its topology table. These feasible successor routes are not used in the forwarding of traffic, but can be injected into the routing table immediately in place of a failed successor route, to avoid the querying process mentioned earlier.

What is the difference between a feasible and a successor?

A successor is the route with the best metric to reach a destination. That route is stored in the routing table. A feasible successor is a backup path to reach that same destination that can be used immediately if the successor route fails. These backup routes are stored in the topology table.

How does EIGRP router work?

By default, an EIGRP router will store only the route with the best (lowest) feasible distance in the routing table (or, multiple routes with equivalent feasible distances). However, under certain conditions, EIGRP will also maintain less-than-optimal routes in its topology table.