A SYN Flood attack is a type of denial of service attack meant to bring a network to its knees by repeatedly bombarding it with useless traffic. This network security failure begins when an attacking source generates TCP packets with random IP addresses and directs them towards the victim host. The host server replies by sending SYN ACK packets to the spoofed source addresses, which fail to respond. Hence, the host's finite-sized queue of connections waiting to be completed is filled, and before these half-open connections can time out, legitimate requests are denied. Because the IP addresses are spoofed, the source is difficult to identify. However, network security solutions to monitor traffic and limit damage are widely available.