net-monitor

module

v0.3.9 Latest Latest Go to latest Published: Jul 11, 2026 License: MIT

Details

Simple terminal network monitor. It captures packets from an active network interface and shows aggregated connection statistics in the console.

On macOS/Linux, packet capture usually requires sudo.

go install github.com/ikondratev/net-monitor/cmd/net-monitor@v0.3.8

Or install the latest tagged release:

go install github.com/ikondratev/net-monitor/cmd/net-monitor@latest

Make sure Go's bin directory is in your PATH:

export PATH="$HOME/go/bin:$PATH"

Check the installed version:

net-monitor -v

Run:

sudo net-monitor

List available interfaces:

net-monitor -si

Capture from a specific interface:

sudo net-monitor -i en0

Supported flags:

Flag	Description
`-v`	Print version and exit.
`-si`	Show available network interfaces and exit.
`-i <name>`	Capture from a specific network interface.
`--interface <name>`	Same as `-i`.
`-p <port>`	Filter TCP/UDP traffic by port.
`--proto <tcp\|udp\|icmp>`	Filter traffic by protocol.
`--host <ip>`	Filter traffic by host IP address.
`--bpf <filter>`	Use a custom BPF filter. Overrides the generated filter.
`--dump <pcap\|json>`	Write captured packets to stdout instead of starting the UI.
`--limit <count>`	Stop after capturing this many packets. Use with `--dump` to create bounded captures.

Filter by protocol, host, or port:

sudo net-monitor --proto tcp
sudo net-monitor --host 192.0.2.10
sudo net-monitor -p 443

Use a custom BPF filter:

sudo net-monitor --bpf "tcp and host 192.0.2.10 and port 443"

Dump captured packets to a pcap file:

sudo net-monitor --bpf "tcp and port 443" --dump pcap --limit 100 > traffic.pcap

Dump captured packets as NDJSON (one JSON object per line):

sudo net-monitor --proto tcp --dump json --limit 50 > traffic.json

Inspect the JSON dump with jq:

cat traffic.json | jq .

Read the saved capture with tcpdump:

tcpdump -nn -r traffic.pcap

go build -o bin/net-monitor ./cmd/net-monitor

Check the embedded version:

./bin/net-monitor -v

Run:

sudo ./bin/net-monitor

Path	Synopsis
cmd
net-monitor command
lib
app Package app wires packet capture, statistics aggregation, and the UI.	Package app wires packet capture, statistics aggregation, and the UI.
cli Package cli parses net-monitor command-line flags and runs the application	Package cli parses net-monitor command-line flags and runs the application
consoleui Package consoleui renders terminal UI for net-monitor.	Package consoleui renders terminal UI for net-monitor.
netcapture Package netcapture opens a network interface and streams packets with BPF filtering.	Package netcapture opens a network interface and streams packets with BPF filtering.
netdevice Package netdevice discovers network interfaces available for packet capture.	Package netdevice discovers network interfaces available for packet capture.
netdump Package netdump writes captured packets to stdout in pcap or JSON format.	Package netdump writes captured packets to stdout in pcap or JSON format.
netinterface Package netinterface defines connection identity and traffic statistics types.	Package netinterface defines connection identity and traffic statistics types.
netstats Package netstats aggregates captured packets into per-connection statistics.	Package netstats aggregates captured packets into per-connection statistics.