Comparing Hash Function Algorithms for the IPv6 Flow Label

Abstract

We compare several stateless hash algorithms for generating IPv6 flow labels, by testing them against trace files of IPv6 traffic measured at four different sites. The criteria for comparison were uniformity of the resulting distribution of hash values and computing time. Of the algorithms tested, we recommend FNV1a-32. We also note how the hash values may be made hard for a third party to predict.