NetFlow v9 parser, collector and analyzer implemented in Python 3. Developed to be used with softflowd v0.9.9
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src/netflow Add additional field types (ASA, PANOS) and set fallback type to 0 Jun 15, 2018
.gitignore Add JSON export and analyzing example script Oct 28, 2017
LICENSE Bump to 0.6; expand analyzer Oct 29, 2017 Fix missing IP_PROTOCOL_VERSION field in analyzer Feb 20, 2018 Fix missing IP_PROTOCOL_VERSION field in analyzer Feb 20, 2018 Fix missing IP_PROTOCOL_VERSION field in analyzer Feb 20, 2018

Python NetFlow v9 parser and UDP collector

This script is able to parse incoming UDP NetFlow packets of NetFlow version 9.

Version 9 is the first NetFlow version using templates. Templates make dynamically sized and configured NetFlow data flowsets possible, which makes the collector's job harder.

Copyright 2017, 2018 Dominik Pataky

Licensed under MIT License. See LICENSE.

Using the collector and analyzer

In this repo you also find and

To start an example collector run python3 -p 9000 -D. This will run a collector at port 9000 in debug mode. Point your flow exporter to this port on your host and after some time the first ExportPackets should appear (the flows need to expire first).

After you collected some data, exports them into JSON files, simply named <timestamp>.json.

To analyze the saved traffic, run <json file>. In my example script this will look like the following, with resolved hostnames and services, transfered bytes and connection duration:

2017-10-28 23:17.01: SSH     | 4.25M    | 15:27 min | localmachine-2 (<IPv4>) to localmachine-1 (<IPv4>)
2017-10-28 23:17.01: SSH     | 4.29M    | 16:22 min | remotemachine (<IPv4>) to localmachine-2 (<IPv4>)
2017-10-28 23:19.01: HTTP    | 22.79M   | 47:32 min | ( to localmachine-1 (<IPv4>)
2017-10-28 23:22.01: HTTPS   | 1.21M    | 3 sec     | (2a00:1450:4001:818::200e) to localmachine-1 (<IPv6>)
2017-10-28 23:23.01: SSH     | 93.79M   | 21 sec    | remotemachine (<IPv4>) to localmachine-2 (<IPv4>)
2017-10-28 23:51.01: SSH     | 14.08M   | 1:23.09 hours | remotemachine (<IPv4>) to localmachine-2 (<IPv4>)

Feel free to customize the analyzing script, e.g. make it print some nice graphs or calculate broader statistics.


Development environment

I have specifically written this script in combination with NetFlow exports from softflowd v0.9.9 - it should work with every correct NetFlow v9 implementation though.