Dell EMC SmartFabric OS10 User Guide Release 10.5.0

Normal traffic flow without resilient hashing

Traffic flow with resilient hashing enabled

When you enable resilient hashing for ECMP groups, the flow-map table is created with 64 paths (the OS10 default maximum number of ECMP paths) and traffic is equally distributed. In the following example, traffic 1 maps to next hop 'A'; traffic 2 maps to next hop 'C'; and traffic 3 maps to next hop 'B.'

Member link goes down

In the following example, if member link D goes down, resilient hashing distributes the traffic intended for member link D to A and B. The existing 1, 2, and 3 traffic is not disturbed.

Member link is added

However, when a new member link is added, resilient hashing completes minimal remapping for better load balancing, as shown: