SMURF Attack

A broadcast server is a server capable of duplicating a message and sending it to all machines present on the same network. The "smurf" technique is based on the use of broadcast servers to paralyze a network

The scenario of such an attack is as follows:

• the attacking machine sends forged packets that contain the spoofed source address of the attacker's intended victim (i.e. providing the IP address of a target machine) to one or more broadcast servers.
  
• the broadcast server passes on the request to the entire network
  
• all of the network's machines send a response to the broadcast server
  
• the broadcast server redirects the responses to the target machine.
  

As such, when the attacking machine sends a request to several broadcast servers located on different networks, all of the responses from computers on the various networks will be routed to the target machine.

In this way the bulk of the attacker's work involves finding a list of broadcast servers and falsifying the response address in order to direct them to the target machine.