Patent ID: 8352829

Claim:
A network device comprising: a memory that stores a plurality of pre-computed CRCs; a set of one or more network interfaces that receives a packet from a network subsequent to the memory storing the plurality of pre-computed CRCs, the packet including an original group of bits and an original cyclical redundancy check (CRC) associated with the original group of bits, wherein none of the plurality of pre-computed CRCs is computed based on the original group of bits of the received packet; CRC selection circuitry that selects at least one of the plurality of pre-computed CRCs, the CRC selection circuitry being in electrical communication with the memory; first addition circuitry that receives an original group of bits of the packet and a modified version of the group of bits and performs a first addition operation on the original group of bits and the modified version of the group of bits to produce a first addition operation output, the original group of bits differing from the modified version of the group of bits; multiplier circuitry that multiplies the selected at least one of the plurality of pre-computed CRCs with the output of the first addition operation on the original group of bits and the modified version of the group of bits, wherein the multiplier produces a multiplier output, and wherein the multiplier is in electrical communication with the memory; CRC computation circuitry that produces a CRC computation circuitry output from the multiplier output, wherein the CRC computation circuitry is in communication with the multiplier circuitry and the first addition operation circuitry; second addition circuitry that performs a second addition operation on the CRC computation circuitry output and the original CRC associated with the original group of bits of the packet to output a modified CRC associated with the modified version of the group of bits, the second addition circuitry being in communication with the CRC computation circuitry; and a forwarding component that updates the original CRC of the packet with the modified CRC and outputs the packet to the network via the set of network interfaces.