ethtool

Query and control network driver and hardware settings.

medium risk

interactive breakdown — edit the command and press Explain
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⚠ Risks & cautions
What it does

ethtool queries and configures Ethernet device settings: link speed, duplex, offload features, driver info, and statistics. Essential for NIC performance tuning, diagnosing link issues, and verifying network card capabilities.

Common flags
FlagMeaning
-i --driverShow driver info for a device
-S --statisticsShow NIC statistics
-k --show-featuresShow offload features
-K --featuresEnable/disable offload features
Examples
ethtool eth0Show link speed, duplex, and auto-negotiation status · explain & risk-check →
ethtool -i eth0Show driver and firmware version · explain & risk-check →
ethtool -S eth0 | grep -i dropCheck for dropped packets at NIC level · explain & risk-check →
ethtool -k eth0 | grep tx-checksummingCheck if TX checksum offload is enabled · explain & risk-check →
Pro tip

Run `ethtool -S eth0 | grep -i 'drop\|error'` when diagnosing packet loss — NIC-level drops are invisible to application-level monitoring and often missed.

Related
ip ss dmesg
Open the full explainer →More in Networking

Reference text is hand-written and may be incomplete — check man ethtool for your version. Test destructive commands on a non-production system first.