What causes packet loss
Congestion: under load, buffers fill and switches drop what will not fit. Failing hardware: dying NICs, switch ports, and degrading optics. Cables and fiber: damaged, dirty, or unseated cables and connectors. Configuration and software: duplex mismatch, MTU issues, firmware bugs, QoS mistakes.
Solving packet loss hop by hop
You solve packet loss by locating it. Use continuous path testing to find the hop that drops traffic, then read the interface counters at both ends: CRC errors point to cable or optics, queue drops point to congestion, port resets point to hardware or firmware. Key advantages: per-hop tests rather than just end-to-end, reading error counters at both ends, CRC errors → cable/optics, queue drops → congestion, track optical levels before they fail.
FAQ
Packet loss is when a packet traveling across a network fails to reach its destination. Above roughly 1%, real-time apps degrade; sustained loss on a data center network usually means hardware or congestion. Acceptable loss: a wired data center network should be near zero — sustained loss above 0.1% warrants investigation.