https://www.netdata.cloud/tags/network-interfaces/Recent content in Network interfaces on NetdataHugoen-ushttps://www.netdata.cloud/guides/network/network-interface-flapping/Mon, 01 Jan 0001 00:00:00 +0000https://www.netdata.cloud/guides/network/network-interface-flapping/<p>Interface flapping is when a network interface oscillates rapidly between up and down states. Each transition generates a linkDown/linkUp trap pair, syslog entries, and an STP topology change notification. At low rates this is operational noise. At high rates it becomes a multi-layer failure: the trap receiver overflows, the syslog pipeline saturates, STP reconvergence flushes MAC tables across the VLAN, and the monitoring platform reports misleading availability because the poll interval is slower than the flap cadence.</p>https://www.netdata.cloud/guides/network/network-interface-errors/Mon, 01 Jan 0001 00:00:00 +0000https://www.netdata.cloud/guides/network/network-interface-errors/<p>A switch port reports 47,000 input errors and climbing. The interface is up and traffic is flowing. Your monitoring fired an alert on ifInErrors crossing threshold. Now you need to determine whether this is a dirty fiber, a dying SFP, a duplex mismatch, buffer exhaustion, or a counter artifact from an interface flap.</p> <p>ifInErrors (.1.3.6.1.2.1.2.2.1.14) and ifOutErrors (.1.3.6.1.2.1.2.2.1.20) are aggregate counters. They tell you something is wrong, but not what. The counter is a sum of multiple error types: CRC, alignment, runts, giants, overruns, frame errors, and on some platforms, input drops. A frame that arrives with both a CRC error and a runt condition increments ifInErrors by exactly 1, not 2. You cannot reconcile the sub-counters against the aggregate by simple addition.</p>