TL-SL3428_V3_User_Guide - TP-Link

DoS Attack TypeDescriptionScan SYNFIN The attacker sends the packet with its SYN field and the FIN field set to 1.The SYN field is used to request initial connection whereas the FIN field isused to request disconnection. Therefore, the packet of this type is illegal.The switch can defend this type of illegal packet.XmascanNULL Scan AttackSYN packet with its source portless than 1024Ping FloodingSYN/SYN-ACK FloodingThe attacker sends the illegal packet with its TCP index, FIN, URG andPSH field set to 1.The attacker sends the illegal packet with its TCP index and all the controlfields set to 0. During the TCP connection and data transmission, thepackets with all the control fields set to 0 are considered as the illegalpackets.The attacker sends the illegal packet with its TCP SYN field set to 1 andsource port less than 1024.The attacker floods the destination system with Ping broadcast stormpackets to forbid the system to respond to the legal communication.The attacker uses a fake IP address to send TCP request packets to theServer. Upon receiving the request packets, the Server responds withSYN-ACK packets. Since the IP address is fake, no response will bereturned. The Server will keep on sending SYN-ACK packets. If the attackersends overflowing fake request packets, the network resource will beoccupied maliciously and the requests of the legal clients will be denied.Table 11-1 Defendable DoS Attack TypesOn this page, you can enable the DoS Defend type appropriate to your need.Choose the menu Network Security→DoS Defend→DoS Defend to load the following page.Figure 11-16 DoS DefendThe following entries are displayed on this screen:‣ Config156