This thesis describes DNS protocol and messages it uses to obtain desired information. The protocol is described from its creation and occasions that caused the creation of the protocol. Later on are discussed multicast capabilities of name resolution this section is focused on mDNS and LLMNR. In the second part is detailed description of the structure of the messages and their useage. In the last part is described the design of the application, which was based on the specifications listed in RFCs. One chapter is devoted to a detailed description of the application and its individual parts. A large part is devoted to the testing. There are also described problems that occurred during application development and their solutions.

This thesis deals with the modifications of the framework designed for DNS servers testing. Framework is developed by NIC.CZ association and is used primarily for testing the DNS server Knot DNS. The aim of this work are modifications of the framework that will allow simpler testing with this framework, such as: support for multiple implementations of DNS servers, parallel testing, components dummy server and box-in-the-middle, division into multiple components and overall modification of the existing framework. Introduction of thesis is dedicated to the authoritative DNS servers and to the foundations of testing. The remaining part of the thesis deals with the state of the existing framework and the state and testing of modified framework.

This master's thesis is focused on extension of the DPDK DNS Probe application that monitors DNS traffic in high speed networks. It presents framework DPDK, which can be used for fast packet processing. General architecture of the DNS system is described as well as details of its components. Basic principles of transport protocol TCP are described. It introduces an effective design and implementation of DNS packet parsing to optimize DPDK DNS Probe's performance. It also introduces a design and implementation of processing DNS messages sent over TCP for export of traffic statistics. The application's performance was tested using a high speed traffic generator Spirent.

The work analyze current detection methods of anomalies and security incidents in DNS traffic, and than design new obfuscation techniques which are capable of evading anomaly detection. Network attacks, exploiting the DNS protocol for tunneling of other network traffic, were selected for implementation part of the work. Control of botnet is considered as malicious application of tunneling through the DNS protocol. The main result of the work is to emphasize the necessity of discovering new detection principles of anomalies and security incidents in DNS traffic.