1. A method of processing network traffic, the method comprising: receiving a network packet by a network device; determining if the network packet is initiating a network connection; identifying, from among a plurality of rules, a matching rule matching the network packet in response to the determination that the network packet is initiating a network connection, wherein the identified matching rule is identified separately from at least one nonmatching rule not matching the network packet; evaluating the identified matching rule on the network packet in response to the identified matching rule matching the network packet to determine if the network packet should be accepted or passed-through, wherein at least one nonmatching rule is skipped in evaluating the network packet and the identified matching rule is evaluated in an order specified by a rule list; determining if there is sufficient processing capacity to handle the network packet and an associated network connection in response to the identified matching rule indicating that the network packet should be accepted; determining if there is sufficient processing capacity to handle the network packet and the associated network connection in response to the network packet not matching any rules; accepting the network packet in response to the determination that there is sufficient processing capacity to handle the network packet; selecting at least one of a plurality of additional devices to be a selected additional device, wherein selection is based on load balancing the network traffic among the plurality of additional devices; passing the network packet through to the selected device in response to the identified rule indicating that the network packet should be passed-through; and passing the network packet through to the selected device in response to the determination that there is not sufficient processing capacity; wherein the network device is connected with the selected device in a serial cluster, wherein the network devices in the serial cluster are configured to not respond to auto-discovery probe messages from each other.