Network & Infrastructure / Linux Networking & Host Performance
Transmit queue stalls with a healthy physical link
A Linux host temporarily stops transmitting on one queue while link state remains up. Driver, firmware or queue-processing issues can differ from ordinary congestion loss.
Environment and inputs: Linux network namespaces, host routing and network drivers; availability and semantics depend on kernel and driver versions. Diagnostic/design example; not tested on production equipment.
Collect the evidence
Record driver messages, per-queue transmit progress, watchdog events, firmware version and switch-side observations. Compare the affected queue with others and preserve evidence before resetting the interface.
Explain the result
Carrier state describes physical link availability, not continuous progress through every transmit queue. A stalled queue can hold selected flows while unrelated traffic still passes.
Plan the fix
Use the vendor-supported driver/firmware and recovery procedure, with a narrow reproduction case where possible. Avoid repeatedly resetting production links without preserving the queue-specific evidence.
Check the result and rollback
Validate queue progress and application traffic under the original workload, including offload combinations. Restore the prior supported software stack if an update introduces new stalls or compatibility problems.