Cisco CCNA mock exam questions sample test – Question 209

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

A. EIGRP will mark the route as passive until a new successor route is determined.
B. EIGRP will redistribute routes into RIP or OSPF.
C. EIGRP will query neighboring routers until a new successor route is determined.
D. EIGRP will forward traffic to the neighbor with the lowest administrative distance.

Correct Answer: C

Feasible successors are backup routes for the successor (active) route to a remote network. If a successor route fails, and a feasible successor is available, the feasible successor
will immediately become the successor and be installed in the routing table. This provides EIGRP with virtually instantaneous convergence. If no feasible successor is available, then
the router must send out query packets to neighboring EIGRP routers to find an alternate path to the remote network.
EIGRP routes are marked as active when the network is converging. Passive routes are stable, converged routes.
EIGRP will not redistribute routes into RIP or OSPF. Redistribution allows information learned from one routing protocol to be converted into routes for injection into the autonomous
system of another routing protocol. This allows networks learned via EIGRP, for example, to be visible and reachable from hosts in a RIP routing domain. Redistribution has nothing to
do with EIGRP convergence or with the determination of a new successor route.
Administrative distance is used to determine which source of routing information is considered more trustworthy when multiple routing protocols have been implemented.
Administrative distance has no effect on EIGRP convergence or the determination of a new successor route.
Routing Fundamentals
Configure, verify, and troubleshoot EIGRP for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub)
Cisco > Support > IP > IP Routing > Technology Information > Technology White Paper > Enhanced Interior Gateway Routing Protocol > Document ID: 16406 > Feasible Distance,
Reported Distance, and Feasible Successor