nDPI

What is nDPI ?

nDPI® is an open source LGPLv3 library for deep-packet inspection.

A generic FAQ about nDPI is available here

How To Compile nDPI

In order to compile this project do

• ./autogen.sh && ./configure
• make

If you get some errors while compiling croaring.c, try:

• ./autogen.sh && ./configure --enable-old-croaring
• make

To compile the library w/o any tools or tests:

• ./autogen.sh && ./configure --with-only-libndpi
• make

Out-of-tree builds are supported:

• ./autogen.sh
• mkdir build
• cd build
• ../configure && make

To run tests do additionally:

• ./tests/do.sh # Generate and check for diff's in PCAP files
• ./tests/do-unit.sh # Run unit tests
• ./tests/do-dga.sh # Run DGA detection test

or run all with: make check

Please note that the (minimal) pre-requisites for compilation include:

• GNU tools (autoconf automake libtool pkg-config gettext flex bison)
• GNU C compiler (gcc) or Clang

On Debian/Ubuntu systems do:

• sudo apt-get install build-essential git gettext flex bison libtool autoconf automake pkg-config libpcap-dev libjson-c-dev libnuma-dev libpcre2-dev libmaxminddb-dev librrd-dev

On Arch Linux:

• sudo pacman -S gcc git gettext flex bison libtool autoconf automake pkg-config libpcap json-c numactl pcre2 libmaxminddb rrdtool

On FreeBSD:

• sudo pkg install gcc git gettext flex bison libtool autoconf automake devel/pkgconf gmake libpcap json-c pcre2 libmaxminddb rrdtool

Remember to use gmake and not make on FreeBSD

On MacOS:

• brew install coreutils gcc git gettext flex bison libtool autoconf automake pkg-config libpcap json-c pcre2 libmaxminddb rrdtool

On Windows:

There are three supported ways to build nDPI:

1. MSYS2 (assuming MSYS2 already installed):

• msys2 -c "pacman --noconfirm -S --needed --overwrite '*' git mingw-w64-x86_64-toolchain automake1.16 automake-wrapper autoconf libtool make mingw-w64-x86_64-json-c mingw-w64-x86_64-crt-git mingw-w64-x86_64-pcre2 mingw-w64-x86_64-libpcap"

2. Mingw-w64

3. Visual Studio (see windows/nDPI.sln)

Note: All Windows versions require npcap with WinPcap compatibility mode enabled.

How To Build The Documentation

• pip install --upgrade pip
• pip install -r doc/requirements.txt
• make doc

Use the builtin python3 webserver to view documentation:

• make doc-view

How To Add A New Protocol Dissector

The entire procedure of adding new protocols in detail:

1. Add new protocol together with its unique ID to: src/include/ndpi_protocol_ids.h
2. Create a new protocol in: src/lib/protocols/
3. Variables to be kept for the duration of the entire flow (as state variables) need to be placed in: src/include/ndpi_typedefs.h in ndpi_flow_tcp_struct (for TCP only), ndpi_flow_udp_struct (for UDP only), or ndpi_flow_struct (for both).
4. Add a new entry for the search function for the new protocol in: src/include/ndpi_private.h
5. Choose (do not change anything) a selection bitmask from: src/include/ndpi_define.h
6. Set protocol default ports in ndpi_init_protocol_defaults in: src/lib/ndpi_main.c
7. Be sure to have nBPF support, cloning PF_RING in the same directory where you cloned nDPI: . You can ignore the error

How to use nDPI to Block Selected Traffic

You can use nDPI to selectively block selected Internet traffic by embedding it onto an application (remember that nDPI is just a library). Both ntopng and nProbe cento can do this.

nDPI Paper Citation

• Deri, Luca, et al. nDPI: Open-source high-speed deep packet inspection 2014 International Wireless Communications and Mobile Computing Conference (IWCMC). IEEE, 2014.

Videos and Presentations

• The Ultimate Guide to nDPI [2025]
• Using nDPI to solve real life problems: from First Packet Classification to Obfuscated Traffic detection [PacketFest, 2025]
• Passive Network Traffic Fingerprinting [FOSDEM, 2025]
• A Deep Dive Into Traffic Fingerprints using Wireshark [SharkFest, 2024]
• Network Traffic Classification for Cybersecurity and Monitoring [FOSDEM, 2022]
• Using nDPI for Monitoring and Security [FOSDEM, 2021]
• Knowing the Unknown: How to Monitor and Troubleshoot an Unfamiliar Network [SharkFest, 2017]

nDPI-Related Projects

• nfstream
• nDPId

DISCLAIMER

While we do our best to detect network protocols, we cannot guarantee that our software is error free and 100% accurate in protocol detection. Please make sure that you respect the privacy of users and you have proper authorization to listen, capture and inspect network traffic.

nDPI is a registered trademark in the US and EU.