ICMP Flood Attack
Internet Control Message Protocol (ICMP) is a connectionless protocol used for IP operations, diagnostics, and errors. An ICMP Flood attack - the sending of an abnormally large number of ICMP packets of any type (especially network latency testing "ping" packets) - can overwhelm a target server that attempts to process every incoming ICMP request, and this can result in a denial-of-service condition for the target server.