Static Member Selection Modes For ECMP and LAG

[dkadia-marvell]

This proposal introduces the below two types of light weight static member selection modes for ECMP/LAG.

• Random
• Round Robin

[rck-innovium]

@JaiOCP @tjchadaga

Summary of the discussion on 11/14/2024

1. [Jai] The option to enable packet spraying is in practice needed at the Switch level and not at a per Next Hop Group level.
2. [Jai] A possible interpretation of SAI_SWITCH_ATTR_ECMP_DEFAULT_HASH_ALGORITHM:SAI_HASH_ALGORITHM_RANDOM is to enable packet spraying at a switch level.
   [Ravi] The only description available in the community is: /** Random-based hash algorithm */. This suggests it is still a hash algorithm i.e., it hashes on some fields of the packet. A possible example of such an algorithm could be: https://patents.google.com/patent/US8503456

Next steps agreed:

[Ravi] and [Jai] to see if there are use-cases for enabling packet-spraying at a per NHG granularity instead of switch level. We should also see what happens to telemetry packets, control packets etc. We will discuss offline over the PR and if needed use a follow up meeting.