Link speed mismatch
Network interface negotiated a speed at least 2x below the NIC's highest advertised mode. Usually physical-layer or autoneg; sometimes PCIe slot bound; rarely a deliberate operator choice on multi-mode NICs (the 2x floor filters the small-gap case).
Remediation
When this rule fires on one of your servers, the dashboard alert detail page renders the full remediation guidance: the command to run, what to verify after, and Furnace's annotation for your specific distro + hardware. Sign in at app.glassmkr.com to see the live alert.