Open Source Deep Packet Inspection Software Toolkit
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What is nDPI ?

nDPI is an open source LGPLv3 library for deep-packet inspection. Based on OpenDPI it includes ntop extensions. We have tried to push them into the OpenDPI source tree but nobody answered emails so we have decided to create our own source tree

How To Compile nDPI

In order to compile this library do

  • ./
  • ./configure
  • make

To run tests do additionally:

  • cd tests; ./

Please note that the pre-requisites for compilation include:

  • GNU tools (autogen, automake, autoconf, libtool)
  • GNU C compiler (gcc)

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) needs to be placed in: /include/ndpi_structs.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_protocols.h
  5. Choose (do not change anything) a selection bitmask from: src/include/ndpi_define.h
  6. Add a new entry in ndpi_set_protocol_detection_bitmask2 in: src/lib/ndpi_main.c
  7. Set protocol default ports in ndpi_init_protocol_defaults in: src/lib/ndpi_main.c
  8. Add the new protocol file to: src/lib/
  9. ./
  10. ./configure
  11. make
  12. make check

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 us just a library). Both ntopng and nProbe cento can do this.


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.

Creating A Source File Tar Ball

If you want to distribute a source tar file of nDPI do:

  • make dist

To ensure that a tar file includes all necessary files and to run tests on distribution do:

  • make distcheck