netkit

A pragmatic Go toolkit for network operations — LAN discovery, OS fingerprinting, port scanning, and MAC vendor lookup.

Built for network engineers who prefer a single binary over a pile of Python scripts.

Features

Module	Description
discovery	ARP-based LAN device discovery
oui	MAC address → vendor/manufacturer lookup
portscan	Concurrent TCP port scanner
fingerprint	OS detection via TCP/IP stack fingerprinting

Install

go install github.com/lybw/netkit/cmd/netkit@latest

Quick Start

# Discover devices on local network
netkit discover 192.168.1.0/24

# Scan ports on a target
netkit portscan 192.168.1.1 -p 22,80,443,8080

# Lookup MAC vendor
netkit oui 00:1A:2B:3C:4D:5E

# OS fingerprint (requires root/admin)
netkit fingerprint 192.168.1.1

As a Library

package main

import (
    "fmt"
    "github.com/lybw/netkit/pkg/discovery"
    "github.com/lybw/netkit/pkg/oui"
)

func main() {
    // Discover devices
    devices, _ := discovery.ARP("192.168.1.0/24")
    for _, d := range devices {
        vendor := oui.Lookup(d.MAC)
        fmt.Printf("%-16s %-18s %s\n", d.IP, d.MAC, vendor)
    }
}

Modules

discovery

ARP scan to find live hosts on a subnet. Returns IP + MAC pairs.

oui

Offline MAC-to-vendor lookup using the IEEE OUI database. Embedded via go:embed, no external files needed.

portscan

Concurrent TCP connect scanner with configurable timeout and worker count.

fingerprint

OS detection by analyzing TCP SYN-ACK responses (TTL, window size, options).

License

MIT