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Grading Checklist

A good response must include:

  • Identifies the root cause: LACP hashing mismatch between server and switch, causing traffic imbalance
  • Explains that the switch is using a different hashing algorithm (e.g., src-mac) than the server (layer3+4), resulting in all return traffic hashing to one link
  • Shows how to inspect LACP state on the server using /proc/net/bonding/bond0
  • Identifies the per-link traffic stats showing the imbalance
  • Explains that both links being UP does not mean traffic is balanced -- LACP does not guarantee equal distribution
  • Explains how LACP hashing works: each side independently decides which link to send traffic on
  • Recommends aligning the hashing algorithm on both sides (e.g., both using layer3+4 / src-dst-ip-port)
  • Mentions that single large flows cannot be split across links (flow-level, not packet-level balancing)
  • Suggests reviewing the switch port-channel configuration for the hashing policy
  • Considers whether the traffic pattern itself is skewed (e.g., one dominant client IP)
  • Does NOT suggest simply adding more links without fixing the hashing