Refer to the exhibit.
Router RTA is the hub router for routers RTB and RTC. The Frame Relay network is configured
with EIGRP, and the entire network is in autonomous system 1. However, router RTB and RTC
are not receiving each other’s routes. What is the solution?
A.
Configure the auto summary command under router eigrp 1 on router RTA.
B.
Issue the no ip split horizon command on router RTA.
C.
Configure subinterfaces on the spoke routers and assign different IP address subnets for each
subinterface.
D.
Check and change the access lists on router RTA.
E.
Issue the no ip split horizon eigrp 1 command on router RTA.
F.
Configure a distribute list on router RTA that allows it to advertise all routes to the spoke
routers.
Explanation:
Split horizon controls the sending of EIGRP update and query packets. When split horizon is
enabled on an interface, these packets are not sent for destinations for which this interface is the
next hop. This reduces the possibility of routing loops.
By default, split horizon is enabled on all interfaces.
Split horizon blocks route information from being advertised by a router out of any interface from
which that information originated. This behavior usually optimizes communications among multiple
routing devices, particularly when links are broken. However, with nonbroadcast networks (such
as Frame Relay and SMDS), situations can arise for which this behavior is less than ideal. For
these situations, you may want to disable split horizon. In this example, routes received by RTB
and RTC are not being sent back out the same serial interface on RTA, so they are not receiving
each other’s routes. Disabling Split horizons on interface S0/0 on RTA will fix this issue.