IPv6 Network Scanner

A fast, lightweight IPv6 link-local network scanner for Linux, Windows and macOS, built on .NET 10, SharpPcap, PacketDotNet and Avalonia. Background: Scanning IPv6 networks.

How it works

IPv6 networks are far too large to sweep, so the scanner uses multicast discovery instead. It sends ICMPv6 echo requests (with a correct checksum, hop limit 255) from the adapter's link-local address to

Group	Meaning
ff02::1	all nodes - every IPv6 host answers
ff02::2	all routers - only routers answer

Every echo reply is matched to our request (ICMPv6 identifier + sequence), so a host answering the router group is reliably flagged as Router. Each group is pinged 3 times (1 s apart) and the scanner listens 2 s afterwards - about 5 seconds in total. The MAC address is looked up in an embedded OUI database to show the manufacturer (randomized/locally administered MACs show as Unknown).

Requirements

• .NET 10 runtime (or use a self-contained build)
• A packet-capture library:
  • Linux: libpcap (sudo apt install libpcap0.8t64, sudo dnf install libpcap)
  • macOS: libpcap is part of the OS
  • Windows: Npcap
• Permission to capture/send raw frames:
  • Linux: run as root or grant capabilities once: sudo setcap cap_net_raw,cap_net_admin=eip ./IPv6-NetScanner (for dotnet run give them to the dotnet host binary or just use sudo)
  • macOS: run with sudo or give your user access to /dev/bpf*
  • Windows: Npcap installed (run as administrator if no adapters show up)

Build & run

dotnet build

# GUI
dotnet run --project src/IPv6NetScanner.Gui

# CLI
dotnet run --project src/IPv6NetScanner.Cli -- --list
sudo dotnet run --project src/IPv6NetScanner.Cli -- -i eth0

Publish self-contained single files:

dotnet publish src/IPv6NetScanner.Gui -c Release -r linux-x64 --self-contained -p:PublishSingleFile=true
dotnet publish src/IPv6NetScanner.Gui -c Release -r win-x64   --self-contained -p:PublishSingleFile=true

Project layout

Path	Content
src/IPv6NetScanner.Core	Scanner, packet builder, adapter discovery, OUI database (no UI dependency)
src/IPv6NetScanner.Gui	Avalonia desktop app
src/IPv6NetScanner.Cli	Command line scanner
tests/IPv6NetScanner.Tests	xUnit tests (checksum, packet layout, vendor lookup)

MAC-address vendor database

src/IPv6NetScanner.Core/Resources/vendorMacs.xml is embedded into the assembly. Source: maclookup.app.

Limitations

• Only the local link is scanned; hosts that drop multicast echo requests (some firewalls, icmp6 echo_ignore_multicast) stay invisible.

License / Copyright

See LICENSE.