Lab Testing

What it does: four lab-shakeout tools in one — throughput, a chaos/latency monitor, a connectivity matrix and a raw socket. In detail: a throughput test (iperf3) to measure real bandwidth between two machines, a chaos/latency monitor that watches a link over time for drops and spikes, a connectivity matrix that checks every host against every check so you can see at a glance what can reach what, and a raw socket (a built-in netcat) that connects to any TCP/UDP port — or listens on one — and shows every byte in hex + ASCII with timestamps. Use it to grab a banner, hand-type an HTTP request, prove a firewall passes a port, or catch what a device is sending (point its syslog/NetFlow at your IP and listen).

What you need: for throughput, iperf3 installed on both ends and an iperf3 server running on the other end (the tool tells you the command). For the matrix, the list of hosts and which checks (ping, a TCP port, etc.) to run. Everything else is point-and-click. On Windows get iperf3 with `winget install iperf3` — the iperf.fr build is Cygwin-based, so if you unzip it by hand keep iperf3.exe AND cygwin1.dll together on PATH, or you'll get "cygwin1.dll was not found".

Safe to run: throughput deliberately floods the link at full speed — don't run it across a production path during business hours. The raw socket sends exactly the bytes you type, and Listen on "All interfaces" opens its port to every network this PC is on. The monitor and matrix are light-touch checks (pings and TCP connects). The raw socket is fine for banners and test ports, but a stray payload at a production service is on you; Listen mode opens a port on this machine until you press Stop — on 127.0.0.1 (this PC only) unless you pick "All interfaces" — and the display stops itself at 64 KB.

Reading results: in the matrix a green cell = that host passed that check, red = failed — a full red row is a host that's down or isolated; a red column is one check failing everywhere (often a firewall or a service that's off). Throughput in Mbps/Gbps tells you if a link performs to spec. The chaos monitor's spikes/gaps mark WHEN a flaky link misbehaves, which is what you need to catch an intermittent fault.