An administrator is capturing traffic with Wireshark and is only seeing ARP traffic. What is the most likely cause of this?

An administrator is capturing traffic with Wireshark and is only seeing ARP traffic. What is the most likely cause of this?

• A. The network interface on which the scan is running is not promiscuous mode
• B. The machine is on a switched network and is therefore only seeing local and broadcast/multicast packets
• C. The administrator did not enable the TCP and UDP option when starting the scan
• D. The network interface on which the scan is running has the ARP_ONLY flag set

Answer: (B)

When capturing traffic on a switched network, devices typically only see the packets that are meant for them or are broadcast/multicast packets. This is due to how switches operate; they route traffic specifically to the intended destination based on MAC addresses, rather than flooding all traffic to all ports as hubs do. As a result, if the administrator is only able to capture ARP traffic, it indicates that the network interface is sitting on a switched network and only has visibility into ARP broadcasts and other local traffic, while unicast traffic to other devices is not visible. In this situation, the administrator is likely connected to a single switch port that only receives ARP requests and replies because ARP operates using broadcast packets to resolve IP addresses to MAC addresses within the local subnet. All other types of traffic, such as TCP and UDP packets meant for other systems, would not be captured unless the machine's network interface was properly configured to operate in a manner that allows viewing all traffic, such as using a network tap or configuring the switch to mirror traffic.

When capturing traffic on a switched network, devices typically only see the packets that are meant for them or are broadcast/multicast packets. This is due to how switches operate; they route traffic specifically to the intended destination based on MAC addresses, rather than flooding all traffic to all ports as hubs do. As a result, if the administrator is only able to capture ARP traffic, it indicates that the network interface is sitting on a switched network and only has visibility into ARP broadcasts and other local traffic, while unicast traffic to other devices is not visible.

In this situation, the administrator is likely connected to a single switch port that only receives ARP requests and replies because ARP operates using broadcast packets to resolve IP addresses to MAC addresses within the local subnet. All other types of traffic, such as TCP and UDP packets meant for other systems, would not be captured unless the machine's network interface was properly configured to operate in a manner that allows viewing all traffic, such as using a network tap or configuring the switch to mirror traffic.