A smurf attack is historically one of the oldest techniques to perform a distributed denial-of-service (DDoS) amplification attack. This attack consists of sending a series of ICMP echo requests with a spoofed source IP address to the network broadcast address. When this echo request is broadcast, all hosts on the LAN should simultaneously reply to the target for each spoofed request received. This technique is less effective against modern systems, as most will not reply to IP-directed broadcast traffic.