System and method for distributing packet processing in an internetworking device

An internetworking device having a set of network interface cards, where each network interface card is able to address and send data to any of the other network interface cards. According to one embodiment, when one of the network interface cards receives a network layer packet that should be forwarded to another one of the network interface cards, a process running on the network interface card that received the network layer packet determines a destination address of the network layer packet and determines whether the destination address matches a network layer address of the internetworking device. If the destination address does not match a network layer address of the internetworking device, the process further determines, based on the destination address of the network layer packet, the network interface card to which the network layer packet should be forwarded. Otherwise the process examines a destination port field within a transport layer packet encapsulated by the network layer packet to determine a destination port number and determines, based at least in part on the destination port number, the network interface card to which the network layer packet should be forwarded. In this manner, transport layer processing does not have to be centralized within the internetworking device. Instead, the present invention allows each network interface card to have a transport layer process, wherein each transport layer process has the same network layer addresses.