Abstract: A network appliance is configured to provide inline traffic inspection for all flow through the device, to selectively intercept based on traffic content or policy, and to modify intercepted traffic content, all without connection termination and re-origination. Content modification may involve substitution of traffic content with smaller or larger content, in which case the device provides appropriate sequence number translations for acknowledgements to the endpoints. This streaming rewrite may occur on a byte-at-a-time basis, while keeping the session alive and without a need to proxy it. The appliance enables transmitted TCP data to be modified inline and then reliably delivered without the overhead of forwarding packets through a full-blown TCP stack. Rather, the approach relies upon an initiator entity's TCP stack for congestion control, as well as the receiving entity's re-transmission behavior to determine how the device manages packets internally.

Abstract: A network appliance is configured to provide inline traffic inspection for all flow through the device, to selectively intercept based on traffic content or policy, and to modify intercepted traffic content, all without connection termination and re-origination. Content modification may involve substitution of traffic content with smaller or larger content, in which case the device provides appropriate sequence number translations for acknowledgements to the endpoints. This streaming rewrite may occur on a byte-at-a-time basis, while keeping the session alive and without a need to proxy it. The appliance enables transmitted TCP data to be modified inline and then reliably delivered without the overhead of forwarding packets through a full-blown TCP stack. Rather, the approach relies upon an initiator entity's TCP stack for congestion control, as well as the receiving entity's re-transmission behavior to determine how the device manages packets internally.

Abstract: A network appliance is configured to provide inline traffic inspection for all flow through the device, to selectively intercept based on traffic content or policy, and to modify intercepted traffic content, all without connection termination and re-origination. Content modification may involve substitution of traffic content with smaller or larger content, in which case the device provides appropriate sequence number translations for acknowledgements to the endpoints. This streaming rewrite may occur on a byte-at-a-time basis, while keeping the session alive and without a need to proxy it. The appliance enables transmitted TCP data to be modified inline and then reliably delivered without the overhead of forwarding packets through a full-blown TCP stack. Rather, the approach relies upon an initiator entity's TCP stack for congestion control, as well as the receiving entity's re-transmission behavior to determine how the device manages packets internally.

Abstract: Improved techniques are disclosed for use in an intrusion prevention system or the like. For example, a method comprises the following steps performed by a computing element of a network. A packet of a flow is received, the flow comprising a plurality of packets, wherein the plurality of packets represents data in the network. A network intrusion analysis cost-benefit value is determined representing a benefit for analyzing the received packet for intrusions in relation to a cost for analyzing the received packet for intrusions. The method compares the network intrusion analysis cost-benefit value to a network intrusion analysis cost-benefit threshold to determine whether analyzing the received packet for intrusions before forwarding the received packet is warranted.

Abstract: Intrusion protection. A first packet en route to a first destination is received. A first value representing a benefit for analyzing the first packet for intrusions in relation to a cost for analyzing the first packet for intrusions is automatically determined. An automatic determination is made that the first value is sufficiently high to warrant an analysis of the first packet for intrusions, and in response, the first packet is analyzed for intrusions. If the analysis of the first packet for intrusions indicates an intrusion, the first packet is discarded without forwarding the first packet to the first destination. A second packet en route to a second destination is received. A second value representing a benefit for analyzing the second packet for intrusions in relation to a cost for analyzing the second packet for intrusions is automatically determined.

Abstract: Improved techniques are disclosed for use in an intrusion prevention system or the like. For example, a method comprises the following steps performed by a computing element of a network. A packet of a flow is received, the flow comprising a plurality of packets, wherein the plurality of packets represents data in the network. A network intrusion analysis cost-benefit value is determined representing a benefit for analyzing the received packet for intrusions in relation to a cost for analyzing the received packet for intrusions. The method compares the network intrusion analysis cost-benefit value to a network intrusion analysis cost-benefit threshold to determine whether analyzing the received packet for intrusions before forwarding the received packet is warranted.