Network intrusion protection

1. A method for intrusion protection, comprising a computing element in a network performing the steps of:

receiving a packet of a flow, the flow comprising a plurality of packets, wherein the plurality of packets represents data in the network;

determining a network intrusion analysis cost-benefit value of said received packet, wherein the network intrusion analysis cost-benefit value represents a benefit for analyzing said received packet for intrusions in relation to a cost for analyzing said received packet for intrusions;

comparing said network intrusion analysis cost-benefit value to a network intrusion analysis cost-benefit threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted; and

responsive to a determination that said analyzing said received packet for intrusions before forwarding said received packet is not warranted, forwarding said received packet, indicating that subsequent packets of the flow should be forwarded, storing said received packet, and determining whether said received packet indicates an intrusion after forwarding said received packet;

wherein said received packet comprises a destination address and wherein forwarding said received packet comprises forwarding said received packet to the destination address.

2. The method of claim 1 , further comprising the step of, responsive to a determination that said analyzing said received packet for intrusions before forwarding said received packet is warranted, determining whether said received packet indicates an intrusion and, responsive to a determination that said received packet does not indicate an intrusion, forwarding said received packet.

3. The method of claim 1 , further comprising the step of, responsive to a determination that said received packet indicates an intrusion, discarding said received packet and indicating that subsequent packets of the flow should be discarded.

4. The method of claim 1 , wherein the step of determining whether said received packet indicates an intrusion after forwarding said received packet is performed responsive to another packet not having been received.

5. The method of claim 1 , wherein said cost for analyzing said received packet for intrusions is based at least in part on a length of the flow which includes said received packet.

6. The method of claim 1 , wherein said benefit for analyzing said received packet for intrusions is based at least in part on a likelihood that said received packet contains an intrusion.

7. The method of claim 1 , wherein the step of comparing said value to a threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted further comprises the step of determining that said computer cannot perform said steps at a rate at which packets are received for processing according to said steps, and in response, increasing said threshold.

8. The method of claim 1 , wherein the step of comparing said value to a threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted further comprises the step of determining that said computer can perform said steps at a substantially faster rate than which packets are received for processing according to said steps, and in response, decreasing said threshold.

9. The method of claim 1 , wherein determining whether said analyzing said stored received packet for intrusions responsive to a determination that said network intrusion analysis cost-benefit value is greater than a current network intrusion analysis cost-benefit threshold.

10. A computer program product for intrusion protection, the computer program product comprising a non-transitory computer usable storage medium having computer usable program code embodied therewith, the computer usable program code comprising computer usable program code configured to perform, in a computing element of a network, the steps of:

receiving a packet of a flow, the flow comprising a plurality of packets, wherein the plurality of packets represent data in the network;

determining a network intrusion analysis cost-benefit value of said received packet, wherein the network intrusion analysis cost-benefit value represents a benefit for analyzing said received packet for intrusions in relation to a cost for analyzing said received packet for intrusions;

comparing said network intrusion analysis cost-benefit value to a network intrusion analysis cost-benefit threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted; and

responsive to a determination that said analyzing said received packet for intrusions before forwarding said received packet is not warranted, forwarding said received packet, indicating that subsequent packets of the flow should be forwarded, storing said received packet, and determining whether said received packet indicates an intrusion after forwarding said received packet;

wherein said received packet comprises a destination address and wherein forwarding said received packet comprises forwarding said received packet to the destination address.

11. The computer program product of claim 10 , the computer usable program code further comprising computer usable program code configured to perform the step of, responsive to a determination that said analyzing said received packet for intrusions before forwarding said received packet is warranted, determining whether said received packet indicates an intrusion and, responsive to a determination that said received packet does not indicate an intrusion, forwarding said received packet.

12. The computer program product of claim 10 , the computer usable program code further comprising computer usable program code configured to perform the step of, responsive to a determination that said received packet indicates an intrusion, discarding said received packet and indicating that subsequent packets of the flow should be discarded.

13. The computer program product of claim 10 , wherein the step of determining whether said received packet indicates an intrusion after forwarding said received packet is performed responsive to another packet not having been received.

14. The computer program product of claim 10 wherein said cost for analyzing said received packet for intrusions is based at least in part on a length of the flow which includes said received packet.

15. The computer program product of claim 10 , wherein said benefit for analyzing said received packet for intrusions is based at least in part on a likelihood that said received packet contains an intrusion.

16. The computer program product of claim 10 , wherein the step of comparing said value to a threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted further comprises the step of determining that said computer cannot perform said steps at a rate at which packets are received for processing according to said steps, and in response, increasing said threshold.

17. The computer program product of claim 10 , wherein the step of comparing said value to a threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted further comprises the step of determining that said computer can perform said steps at a substantially faster rate than which packets are received for processing according to said steps, and in response, decreasing said threshold.

18. A computer system in a network for intrusion protection, said computer system comprising:

at least one memory; and

at least one processor coupled to the at least one memory, the at least one processor being operative to:

receive a packet of a flow, the flow comprising a plurality of packets, wherein the plurality of packets represent data in the network;

determine a network intrusion analysis cost-benefit value of said received packet, wherein the network intrusion analysis cost-benefit value represents a benefit for analyzing said received packet for intrusions in relation to a cost for analyzing said received packet for intrusions;

compare said network intrusion analysis cost-benefit value to a network intrusion analysis cost-benefit threshold to determine whether analyzing said received packet for intrusions before forwarding said received packet is warranted; and

responsive to a determination that said analyzing said received packet for intrusions before forwarding said received packet is not warranted, forward said received packet, indicate that subsequent packets of the flow should be forwarded, store said received packet, and determine whether said received packet indicates an intrusion after forwarding said received packet;

wherein said received packet comprises a destination address and wherein forwarding said received packet comprises forwarding said received packet to the destination address.

19. The computer system of claim 18 , wherein the at least one processor is further operative to, responsive to a determination that analyzing said received packet for intrusions before forwarding said received packet is warranted, determine whether said received packet indicates an intrusion and, responsive to a determination that said received packet does not indicate an intrusion, forward said received packet.

20. The computer system of claim 18 , wherein the at least one processor is further operative to, responsive to a determination that said received packet indicates an intrusion, discard said received packet and indicate that subsequent packets of the flow should be discarded.

21. The computer system of claim 18 , wherein determining whether said received packet indicates an intrusion after forwarding said received packet is performed responsive to another packet not having been received.