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A consultant is reviewing the following output after reports of intermittent connectivity issues:

? (192.168.1.1) at 0a:d1:fa:b1:01:67 on en0 ifscope [ethernet]

? (192.168.1.12) at 34:a4:be:09:44:f4 on en0 ifscope [ethernet]

? (192.168.1.17) at 92:60:29:12:ac:d2 on en0 ifscope [ethernet]

? (192.168.1.34) at 88:de:a9:12:ce:fb on en0 ifscope [ethernet]

? (192.168.1.136) at 0a:d1:fa:b1:01:67 on en0 ifscope [ethernet]

? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en0 ifscope [ethernet]

? (224.0.0.251) at 01:02:5e:7f:ff:fa on en0 ifscope permanent [ethernet]

? (239.255.255.250) at ff:ff:ff:ff:ff:ff on en0 ifscope permanent [ethernet]

Which of the following is MOST likely to be reported by the consultant?
A . A device on the network has an IP address in the wrong subnet.
B. A multicast session was initiated using the wrong multicast group.
C. An ARP flooding attack is using the broadcast address to perform DDoS.
D. A device on the network has poisoned the ARP cache.

View Answer

Answer: D

Explanation:

The gateway for the network (192.168.1.1) is at 0a:d1:fa:b1:01:67, and then, another machine (192.168.1.136) also claims to be on the same MAC address. With this on the same network, intermittent connectivity will be inevitable as along as the gateway remains unreachable on the IP known by the others machines on the network, and given that the new machine claiming to be the gateway has not been configured to route traffic.