F5 Solutions Architect Nathan McMahon explains Election Hash Load Balancing And Persistence (find the iRule in the codeshare here).  He developed this Election Hash solution to address the limitations of the Cache Array Routing Protocol, and it provides a nice alternative to any typical  hash solution that are vulnerable to re-factoring on changes to the server pool.  The complete solution is written up here: Hash Load Balancing and Persistence on BIG-IP LTM

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