What does a large number of errors returned by ethtool typically indicate?

A large number of errors returned by ethtool typically indicate issues with the Network Interface Card (NIC), cable, or switchport. High error rates can suggest physical problems such as faulty cables or connectors, NIC malfunctions, or even misconfigured network settings that lead to packet loss or corruption.

When ethtool reports a significant number of errors, this is often a red flag that requires immediate attention to troubleshoot the underlying cause. By examining the hardware components and ensuring they are functioning properly, one can often identify the source of the errors. This could involve testing and replacing cables, checking the NIC configuration, or investigating potential problems with the switchport to ensure a stable network connection.

While high network traffic can lead to performance degradation, it does not specifically correlate to the errors reported by ethtool. Outdated firmware might cause other performance issues, but the errors are more directly a product of physical layer problems or improper configurations. Normal operation would generally not be characterized by a high number of reported errors, as this would indicate a divergence from expected performance.