Network protocols use multiple paths to route packets between network nodes, such that network capacity is optimally utilized in a scalable manner. Equal cost multipath (ECMP) and weighted cost multipath (WCMP) are routing techniques to balance load across multiple paths between traffic source and destination. Load balancing is typically achieved using a hash function to select the next hop for flows of balanced size. Hash functions are provided by switch hardware, and there is often only a limited number of uncorrelated hash functions. Reuse of correlated hash functions can lead to imbalanced traffic distribution within the network. The present disclosure describes techniques to balance traffic distribution within a network by use of VLAN (virtual local area network) tags as a hash input and by shuffling VLAN tags of packets at switches along a path.
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Zhou, Junlan and Ji, Zhengrong, "Hashing technique to optimally balance load within switching networks", Technical Disclosure Commons, (October 05, 2017)