Patent ID: 6597661
Filing Date: 2003-07-22
Classification: H04L

Abstract:
A method in a computer system for authorizing network packets sent from a source address and port number to a destination address and port number, the method utilizing a packet authorization data structure containing numbered buckets, comprising:receiving a first packet sent from a trusted source address and port number; generating an index key for the first packet by summing its source address, source port number, destination address, and destination port number, then determining the remainder when the sum is divided by a predetermined constant value; to a bucket having as its number the index key generated for the first packet, adding a packet authorization record specifying the source address and port number and destination address and port number of the first packet, the added packet authorization record further specifying an expiration time for the packet authorization record; forwarding the first packet to its destination address and port number; receiving a second packet sent to a trusted destination address and port number; generating an index key for the second packet by summing its source address, source port number, destination address, and destination port number, then determining the remainder when the sum is divided by the predetermined constant value; in a bucket having as its number the index key generated for the second packet, identifying a packet authorization record specifying the source address and port number and destination address and port number of the second packet; if the expiration time specified by the identified packet authorization record indicates that the identified packet authorization record has not yet expired, forwarding the second packet to its destination address and port number; and if the expiration time specified by the identified packet authorization record indicates that the identified packet authorization record has expired, omitting to forward the second packet to its destination address and port number.