An engineer is designing an EIGRP network for a small branch office site where there is only one Layer 3 router.
The engineer wants the router to advertise the local LAN network to remote EIGRP neighbors without sending any unnecessary multicast messages on the local LAN.
Which action should the engineer take?
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A. B. C. D.B.
The correct answer is B. Advertise the local LAN using the network command and the passive-interface feature.
Explanation: In EIGRP, when a network is advertised using the network command, the router will automatically form adjacencies with all EIGRP routers on that network segment and send multicast hello packets to discover other routers on that segment. This can cause unnecessary multicast traffic on the local LAN.
To prevent unnecessary multicast traffic, the engineer should use the passive-interface feature in conjunction with the network command. The passive-interface feature suppresses the sending of EIGRP multicast messages on the specified interface, but the interface remains available for forming adjacencies.
The correct configuration to advertise the local LAN network using the network command and the passive-interface feature would be:
phprouter eigrp <AS number> network <local LAN network> passive-interface <interface> Option A, using a static default route instead of EIGRP, would not allow the router to advertise the local LAN network to remote EIGRP neighbors.
Option C, redistributing the local LAN network using the redistribute connected command, would cause the router to advertise all connected networks, including non-LAN networks, to remote EIGRP neighbors.
Option D, advertising the local LAN subnet as a stub network, would prevent the router from advertising any routes other than the local LAN network to remote EIGRP neighbors, which would not meet the requirement of advertising the local LAN network to remote EIGRP neighbors.