TP-Link TL-SL5428E manual DoS Attack Type Description

With DoS Defend function enabled, the switch can analyze the specific fields of the IP packets and distinguish the malicious DoS attack packets. Upon detecting the packets, the switch will discard the illegal packets directly and limit the transmission rate of the legal packets if the over legal packets may incur a breakdown of the network. The switch can defend several types of DoS attack listed in the following table.

DoS Attack Type	Description
Land Attack	The attacker sends a specific fake SYN packet to the destination Host. Since both
	the source IP address and the destination IP address of the SYN packet are set to
	be the IP address of the Host, the Host will be trapped in an endless circle for
	building the initial connection. The performance of the network will be reduced
	extremely.
Scan 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 is used to
	request disconnection. Therefore, the packet of this type is illegal. The switch can
	defend this type of illegal packet.
Xmascan	The attacker sends the illegal packet with its TCP index, FIN, URG and PSH field
	set to 1.
NULL Scan Attack	The attacker sends the illegal packet with its TCP index and all the control fields
	set to 0. During the TCP connection and data transmission, the packets with all the
	control fields set to 0 are considered as the illegal packets.
SYN packet with its source	The attacker sends the illegal packet with its TCP SYN field set to 1 and source
port less than 1024	port less than 1024.
Smurf Attack	By pretending to be a Host, the attacker broadcasts request packets for ICMP
	response in the LAN. When receiving the request packet, all the Hosts in the LAN
	will respond and send the reply packets to the actual Host, which will causes this
	Host to be attacked.
Blat Attack	The attacker sends the illegal packet with its source port and destination port on
	Layer 4 the same and its URG field set to 1. Similar to the Land Attack, the system
	performance of the attacked Host is reduced since the Host circularly attempts to
	build a connection with the attacker.
Ping Flooding	The attacker floods the destination system with Ping broadcast storm packets to
	forbid the system to respond to the legal communication.
SYN/SYN-ACK Flooding	The attacker uses a fake IP address to send TCP request packets to the Server.
	Upon receiving the request packets, the Server responds with SYN-ACK packets.
	Since the IP address is fake, no response will be returned. The Server will keep on
	sending SYN-ACK packets. If the attacker sends overflowing fake request
	packets, the network resource will be occupied maliciously and the requests of the
	legal clients will be denied.
winNuke Attack	Since the Operation System with bugs can not correctly process the URG (Urgent
	Pointer) of TCP packets, the attacker sends this type of packets to the TCP
	port139 (NetBIOS) of the Host with the Operation System bugs, which will cause
	the Host with a blue screen.
	Table 11-1 Defendable DoS Attack Types

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