CompTIA: Advanced Security Practitioner (CASP) Exam Prep

Answer: D - A smurf attack attempts to use a broadcast ping (ICMP) on a network.

Key Takeaway: In a smurf attack, the attacker sends a broadcast message with a legal IP address. In this case, the attacking system sends a ping request to the broadcast address of the network. The request is sent to all the machines in a large network. The reply is then sent to the machine identified with the ICMP request. The result is a DoS attack that consumes the network bandwidth of the replying system while the victim system deals with the flood of ICMP traffic it receives. This attack is almost completely ineffective today as routers by default do not allow forwarding of packets directed to broadcast addresses. Individual systems can also be configured to not respond to ICMP requests.