"description":"Three interactive network monitoring launchers: iftop (real-time bandwidth per host pair), iptraf-ng (multi-mode traffic monitor) and iperf3 (bandwidth test, server / client mode). Each is installed on first use.",
"description":"Three interactive launchers for real-time network observation and bandwidth measurement: iftop, iptraf-ng and iperf3. Each tool is auto-installed from apt on first use, runs in the foreground, and is exited with the documented keystroke. They do not change the host network configuration; iperf3 generates test traffic.",
"body":"Three interactive monitoring tools, each behind its own menu entry. The first time you launch one, the package is installed silently via <code>apt-get</code>. Subsequent launches start instantly. None of these tools modify the host network configuration."
},
"when":{
"heading":"When to use which",
"headerQuestion":"Question",
"headerUse":"Use",
"rows":[
{
"question":"Who is saturating the link <em>right now</em>?",
"question":"How much bandwidth is actually available between two hosts?",
"use":"iperf3"
}
]
},
"iftop":{
"heading":"Real-time network usage (iftop)",
"body":"Live bandwidth per host pair (source ↔ destination) — like <code>top</code> for traffic. Shows the heaviest flows at the top, with rolling 2/10/40-second averages. Best tool for the question <em>\"why is my uplink saturated?\"</em>.",
"exit":"<strong>Exit:</strong> press <kbd>q</kbd>. ProxMenux shows a reminder dialog before launching.",
"keysTitle":"Useful keys inside iftop",
"keysBody":"<kbd>n</kbd> toggle DNS lookup, <kbd>p</kbd> show port numbers, <kbd>P</kbd> pause display, <kbd>t</kbd> toggle line direction (sent / received / both), <kbd>1</kbd>/<kbd>2</kbd>/<kbd>3</kbd> sort by 2s / 10s / 40s average. <code>man iftop</code> for the full set."
},
"iptraf":{
"heading":"Network monitoring tool (iptraf-ng)",
"intro":"A menu-driven multi-mode traffic monitor. Where iftop answers <em>\"who\"</em>, iptraf-ng answers <em>\"what\"</em>: per-protocol byte/packet counts, TCP connection state tracking, packet size histograms and per-station LAN activity.",
"menuIntro":"On launch you get a five-option menu:",
"headerMode":"Mode",
"headerUseFor":"Use it for",
"rows":[
{
"mode":"IP traffic monitor",
"useFor":"Live TCP / UDP / ICMP / other-IP flow list with byte counters and connection state"
"useFor":"Same as above but for one interface, with packet size and rate detail"
},
{
"mode":"Statistical breakdowns",
"useFor":"Packet size distribution histogram, by TCP / UDP port"
},
{
"mode":"LAN station monitor",
"useFor":"Per-MAC traffic stats for the local broadcast domain"
}
],
"exit":"<strong>Exit:</strong> press <kbd>x</kbd> from any view (or <kbd>Q</kbd> from the main menu). ProxMenux shows a reminder dialog before launching.",
"logTitle":"Logging captures to file",
"logBody":"Each mode offers to log captured stats to <code>/var/log/iptraf-ng/</code>. Useful if you need a record of a traffic spike — leave it running, log to file, review the file afterwards instead of trying to read the live screen."
},
"iperf3":{
"heading":"Bandwidth test (iperf3)",
"intro1":"Measures actual TCP throughput between two hosts. Unlike iftop / iptraf-ng (which observe existing traffic), iperf3 generates synthetic traffic to stress-test the link. Indispensable for answering questions like <em>\"is my 10 GbE actually doing 10 GbE?\"</em> or <em>\"is the bottleneck the NIC, the switch, or the storage?\"</em>.",
"intro2":"iperf3 is a <strong>two-host tool</strong>: one side runs as server (listens on TCP port 5201), the other runs as client (connects, sends data, prints the rate). The ProxMenux launcher asks which mode you want:",
"headerMode":"Mode",
"headerBehaviour":"Behaviour",
"headerCli":"Equivalent CLI",
"rows":[
{
"mode":"Server",
"behaviour":"Listens on TCP 5201 and prints results for each incoming test. Stops on Ctrl+C.",
"cli":"iperf3 -s"
},
{
"mode":"Client",
"behaviour":"Asks for the server IP / hostname, connects, runs a default 10-second test and prints the report.",
"cli":"iperf3 -c <target>"
}
],
"workflowIntro":"Typical workflow to test a 10 GbE link between two Proxmox hosts:",
"workflow":[
"On host A, open the Network menu → <em>Bandwidth test (iperf3)</em> → choose <strong>Server</strong>.",
"On host B, open the same menu entry → choose <strong>Client</strong> → enter host A's IP.",
"Wait 10 seconds. Compare the reported rate to the link's theoretical maximum."
],
"sample":"Sample client output:",
"flagsTitle":"Useful manual flags (run from a shell)",
"flagsBody":"<code>-t 60</code> longer test (60s instead of default 10s), <code>-P 4</code> 4 parallel streams (saturates faster), <code>-R</code> reverse direction (server → client), <code>-u -b 100M</code> UDP test at 100 Mbit/s (for jitter / packet loss measurements), <code>-p 5202</code> use a different port (multiple tests in parallel). <code>man iperf3</code> for the full set.",
"firewallTitle":"Open the firewall port on the server",
"firewallBody":"The server listens on TCP <strong>5201</strong> by default. If you run the server inside a Proxmox host with a strict firewall (datacenter or host level), allow inbound TCP 5201 from the client's IP for the duration of the test, then close it again. Same applies to <code>nftables</code> / <code>iptables</code> on bare hosts."
},
"install":{
"heading":"First launch installs the package",
"body":"All three launchers check for the binary and run <code>apt-get update -qq && apt-get install -y <pkg></code> if missing. The install is silent: the menu may appear frozen for 10–30 seconds the first time. Subsequent launches start instantly."
},
"troubleshoot":{
"heading":"Troubleshooting",
"hangTitle":"Install hangs forever on first launch",
"hangBody":"The host has no internet or the apt repos are unreachable. Cancel with <kbd>Ctrl</kbd>+<kbd>C</kbd>, run <code>apt-get update</code> manually to see the actual error (DNS, repo signature, proxy …), then come back to the menu.",
"refusedTitle":"iperf3 client: \"unable to connect to server: Connection refused\"",
"refusedBody":"Either the server is not running, or its firewall blocks TCP 5201. Confirm on the server: <code>ss -tlnp | grep 5201</code> — should show iperf3 listening. If listening but client still fails, check the firewall path between the two hosts.",
"slowTitle":"iperf3 reports way less than the expected link speed",
"slowBody":"Common causes, in order of likelihood: (1) one of the hosts is bottlenecked on CPU — try <code>iperf3 -c <target> -P 4</code> to use multiple cores; (2) the path goes through a slower link (gigabit switch in the middle of two 10 GbE NICs); (3) MTU mismatch — check <code>ip link show</code> on both ends; (4) NIC offloading disabled — see the <em>Disable NIC Offloading</em> community script if you have an Intel e1000e card.",
"noTrafficTitle":"iftop / iptraf-ng show no traffic for a busy host",
"noTrafficBody":"Default capture is on the first detected interface. Specify the right one explicitly from the shell: <code>iftop -i vmbr0</code> or <code>iptraf-ng -i vmbr0</code>. The menu launcher uses the default; for non-default interfaces, run from a console."
},
"related":{
"heading":"Related",
"items":[
{
"label":"Diagnostics",
"href":"/docs/network/diagnostics",
"tail":" — the read-only one-shot checks (routing, connectivity, advanced stats)."
},
{
"label":"Bridge analysis & guided repair",
"href":"/docs/network/bridge-analysis",
"tail":" — when monitoring reveals an interface or bridge isn't doing what it should."
