Patent ID: 7464398

Claim:
An apparatus for protecting network devices connected to a communications network against service disrupting attacks, comprising: at least two queues for queuing packets according to a level of trust assigned to the respective queue; a source address table for each of said queues, the source address table listing addresses of all sources in said communication network having the level of trust assigned to the respective queue wherein said source address tables have relative levels of trust ranging from legitimate to unknown; a decision engine for receiving packets from the communications network and queuing each of the packets in the queues in dependence upon a source address of the respective packet as identified in said source address table; and a scheduler for de-queuing packets from the queues for transmission to the network devices, wherein packets from the queues with a higher level of trust are de-queued at a higher rate than packets from a queue with a lower level of trust, and further comprising means to count a multiple number of times a source address is identified in the incoming packets and to place said source addresses in a source address table associated with a high level of trust after receiving N packets with said source address, where N is a positive integer exceeding a specific threshold.