The Land attack involves the perpetrator sending spoofed packet(s) with the SYN flag set to the victim’s machine on any open port that is listening. The packet(s) contain the same destination and source IP address as the host, causing the victim’s machine to reply to itself repeatedly. In addition, most systems experience a total freeze up, where as CTRL-ALT-DELETE fails to work, the mouse and keyboard become non operational and the only method of correction is to reboot via a reset button on the system or by turning the machine off.
The Boink attack, a modified version of the original Teardrop and Bonk exploit programs, is very similar to the Bonk attack, in that it involves the perpetrator sending corrupt UDP packets to the host. It however allows the attacker to attack multiple ports where Bonk was mainly directed to port 53 (DNS).
The Teardrop attack involves the perpetrator sending overlapping packets to the victim, when their machine attempts to reconstruct the packets the victim’s machine hangs.
A Smurf attack is a network-level attack against hosts where a perpetrator sends a large amount of ICMP echo (ping) traffic at broadcast addresses, all of it having a spoofed source address of a victim. If the routing device delivering traffic to those broadcast addresses performs the IP broadcast to layer 2 broadcast function, most hosts on that IP network will take the ICMP echo request and reply to it with an echo reply each, multiplying the traffic by the number of hosts responding. On a multi-access broadcast network, there could potentially be hundreds of machines to reply to each packet.
Resources: http://en.wikipedia.org/wiki/Denial-of-service_attack http://en.wikipedia.org/wiki/LAND