Patent ID: 7492713

Claim:
A network router comprising: a chassis having a plurality of slots to receive removable cards; a plurality of removable interface cards inserted within the slots to receive packets from a network; a plurality of removable accounting service cards inserted within the slots to calculate statistics for flows of the packets; a plurality of removable packet analysis cards inserted within the slots; and a control unit configured to distribute the packets to the accounting service cards for calculation of the flow statistics prior to analysis by the packet analysis cards, wherein, after calculation of the flow statistics, the control unit intercepts packets for a subset of the flows for which the flow statistics indicate traffic levels exceed a threshold indicative of a potential network attack, wherein the control unit forwards the intercepted packets to the packet analysis cards, wherein the packet analysis cards analyze contents of the intercepted packets to determine the presence of the network attack, and wherein the control unit updates routing information based on the determination of the packet analysis cards and routes the packets in accordance with the routing information.