1. A method of correcting reduction operations in a presence of packet corruption in a multi-node computer network, the method comprising: a first node of the network sending an operand packet to a second node of the network over a link between the first and second nodes, said packet including one or more operands; the first node keeping a copy of the packet on a sending end of the link until the first node receives an acknowledgment from the second node that the packet was received by the second node without error; the second node transmitting the packet to one or more additional nodes of the network; the second node testing the packet to determine if the packet is error free; and if the second node determines that the packet is not error free, then the second node setting a flag in the packet to mark the packet as corrupt, transmitting the set flag in the packet to said one or more additional nodes, returning an acknowledgement to the first node which specifies that the packet was received with error, and requesting retransmission of the packet; returning the link to a known state, and the first node retransmitting the packet to the second node; and when the re-transmitted packet arrives at the second node, repeating a reduction computation utilizing stored copies of uncorrupted packets.