An EIGRP network is configured with default settings for all the routers, shown in the exhibit. Traffic is not routing correctly.
What commands need to be run, and on which router should it be run?
A. The ip summary-address eigrp 500 172.16.0.0.0 255.255.0.0 command should be run on Router D.
B. The ip summary-address eigrp 500 172.16.3.0.0 255.255.255.0 command should be run on Router C.
C. The no auto-summary command should be run on Routers A, B, C and F
D. The auto-summary command should be run on Router D.
Explanation:
The no auto-summary command should be run on Routers A, B, C and F. When discontinuous networks exist in the network, as in this one, the auto summarization feature will prevent proper routing. Auto summarization is enabled by default.
Discontinuous networks are subnets of a classful parent network address not located in the same area of the network. Because Routers A, B, C and F will all advertise a 10.0.0.0/8 network Router D will not only think that the 10.0.0.0/8 network is on two different directions it will be unable to discern the individual subnets connected to each, leading to connectivity issues. Executing the no auto-summary command on those three routers will allow them to advertise subnets, clearing up the routing confusion created by auto summarization.
The ip summary-address eigrp 500 172.16.0.0.0 255.255.0.0 command should not be run on Router D. This will manually configure the same summarization that is already occurring automatically, and will not solve the issue.
The auto-summary command should not be run on Router D. This function is already being performed automatically and is the source of the routing problem. It should be disabled instead.
Objective:
Layer 3 Technologies
Sub-Objective:
Configure and verify manual and autosummarization with any routing protocol