IP networks play an essential role in many fields of our daily lives, both in terms of business as well as our everyday communication. It has become crucial to constantly monitor their performance and traffic, which helps us react to anomalies in time and consequently, to optimalize the network.
After a short introduction, in the second chapter of my thesis I introduce the functions, and the different versions of the NetFlow protocol developed by Cisco for passive network monitoring, and I show how and where it can be used effectively. In the third chapter I introduce open source NetFlow exporter, collector and analyzer softwares for Ubuntu operating system. In my thesis work I implemented a Linux kernel module in C programming language for NetFlow exporting. In the next part I elaborate on the steps of the development and the software’s usage. In the fifth chapter I describe the test environment and evaluate the measurement’s data. In the last part I suggest some possible future improvements and summarize my work.