An Efficient High-Throughput and Low-Latency SYN Flood Defender for High-Speed Networks

Algorithm 2

Decision generation.

Input: SYNFlood, Protocol, TCP_flag, ACK_number, Index, Cookie

Output: Decision, Cookie

1  Decision = Bypassing;

2  if (incoming packet) (SYNFlood = true)  then

3if  Protocol = TCP  then

4if  TCP_flag = SYN_flag  then

5Response phase:

6if  packet known clients  then

7Forget the client;

8Decision = Bypassing;

9else

10Decision = Converting SYN to SYN-ACK;

11else if  TCP_flag = ACK_flag  then

12Authentication phase:

13if  Cookie = ACK_number - 1  then

14Add to known clients;

15Decision = Converting ACK to RST;

16else

17Decision = Bypassing;

18  return  Decision, Cookie