Patent ID: 6782424
Filing Date: 2004-08-24
Classification: G06F,H04L

Abstract:
A computer program embodied on a computer readable medium for defeating a denial of service attack, wherein the computer program runs as an application of a real-time supervisory operating system, which runs a secondary operating system as an application thereof, the computer program comprising:a computer code segment that scans all TCP control blocks in the secondary operating system; a computer code segment that, for each of said control blocks, performs the following acts: determines whether the control block indicates that the state of the TCP port associated with the control block is SYN_RECEIVED and increments a counter if it is determined that the state of the TCP port is SYN_RECEIVED; a computer code segment that determines whether the value of the counter is greater than a first configurable threshold; and a computer code segment that sets a denial of service attack warning flag to TRUE if the counter is determined to be greater than the first configurable threshold.