Abstract: Embodiments are directed towards selecting a local port number for server side connections that hash to a same processor as a matching client side flow on a multiprocessor device using Receive Side Scaling (RSS) for the disaggregation hash. A hash of a flow key is computed with an initial port number. An exclusive-or (XOR) distance is computed to a desired hash, using least significant bits. An XOR is performed on a corrected pre-computed collision value, to transform the source port number to a value that hashes correctly with other elements within the flow key. The transformed source port number may then be inserted into network packets sent to a server device, such that the transformed source port number can be used in a returning RSS hash to again select the same processor.