To defend against network mapping, which of the following packets should be denied at the border router?
To defend against network mapping, which of the following packets should be denied at the border router?
To defend against network mapping, incoming ICMP Echo Request messages should be denied at the border router. ICMP Echo Request messages are used in network discovery processes, such as ping sweeps, to identify active devices on a network. By blocking these incoming messages, you can prevent external entities from probing your network and mapping out its structure.
ICMP Echo Request messages are commonly used by network mappers (such as ping sweeps) to determine which IP addresses are live and responsive. By denying incoming ICMP Echo Request messages at the border router, you can prevent external entities from probing your network using ping sweeps or similar techniques, thereby reducing the visibility of your network to potential attackers.
I think the answer is D here.