A water-utility cluster spans VPN-connected racks. Large pod-to-pod payloads stall while small pings work. What networking issue fits this pattern?
Select an answer to reveal the explanation.
Short Explanation
Tiny postcards get through; fat packages vanish in the VPN tunnel—classic MTU black hole. Match MTU across the path or lower the overlay size.
Full Explanation
When a water-utility cluster spans VPN-connected racks and large pod-to-pod payloads stall while small pings work, the networking issue that fits is MTU mismatch or path MTU black holes across the VPN/overlay path dropping oversized packets. Tiny postcards get through; fat packages vanish in the tunnel. RBAC Roles that omit get on pods/log block log API access, not only large TCP segments between pods. etcd snapshot schedules do not pause NodePort listeners during compaction as an explanation for large-payload stalls. HPA maxReplicas set below one is invalid/odd configuration and does not truncate packets over 512 bytes. Exam caveat: Lower overlay MTU or fix VPN MSS clamping. On the exam, link “small works, large fails” to MTU/PMTUD. Operational check: Trace path MTU between racks, set CNI/overlay MTU appropriately, retest large transfers for utility apps, and document the MTU standard for VPN-linked civic racks. In municipal production practice, record the finding in the incident ticket with command output snippets, confirm the fix under change control, and re-validate the user-facing civic service before closing the change window. In municipal production practice, record the finding in the incident ticket with command output snippets, confirm the fix under change control, and re-validate the user-facing civic service before closing the change window.