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The subject of this work relates to monitoring of large networks consisting of hundreds of active elements and thousands of users. Study of the subject is situated in the Kolejnet computer network environment, where information system is being used. At the moment, the information system includes basic monitoring of this large network. The goal [of this study] is to architect a system that will allow continuous monitoring of active elements which includes collection of data and logging of important events for immediate and later evaluation of serious circumstances that can arise.

This diploma thesis deals with analysis, modeling and simulation of the IEEE 802.11af wireless communication system on the physical layer. When designing the solution, it is necessary to understand in details the features and specifics of the IEEE 802.11af system. The work is primarily describes the transmitting part of the communication system with emphasis on processing IEEE 802.11af signal. Subsequently the block diagram and the basic model are created for the transmitting and receiving parts in SISO and MISO broadcast modes. The model is implemented with graphical user interface in the MATLAB programming environment. This application is used to explore the features and performance of the IEEE 802.11af based on its system parameters. System parameters are user configurable what allows to simulate different scenarios. The application also supports simulation of fading channel.

This master's thesis focuses on computer network design of multiple Občanům, s.r.o. company branches. The design consists of creating complete implementation documentation according to investor demands, which also includes passive and active network components, and specific security technologies.

This diploma thesis deals with the proposal and the maintenance of Ethernet computer networks in the Department of Telecommunication property in Brno. There is a description of communication line types used in LAN computer networks in the first parts of the work. Their advantages and disadvantages are introduced too. Further there is an existing situation of the computer network on the third and the fourth floor of the Department of Telecommunication building documented. This documentation includes a design and a list of used components. The existing computer network has some minor inadequacies that were taken into consideration in the new proposal. There is a completely elaborate documentation of the new proposed network on the third and the fourth floor that contains a detailed placement and a single component configuration including their description. This documentation should significantly contribute to more effective network maintenance in the future. The computer network maintenance does not contain only servers, printers or workstations. It's also necessary to consider network parts that are not so perceptible for common users. That means single segments of computer networks with its active devices. A web based application for the effective computer network maintenance is proposed and described in this work too. The application allows administrator to keep a well-arrange view of the single network segments. All network related information is saved into a database that can help with a solution of later occurred problems.

Tématem této diplomové práce (dále jen DP) je návrh rozsáhlých podnikových sítí podle doporučení stanovených společností Cisco. Dále je realizována simulace navržené topologie prostřednictvím programů s otevřeným zdrojovým kódem a dohled nad sítí prostřednictvím programu Nagios. Úvodní část obsahuje stručné seznámení se základním rozdělením sítě do jednotlivých funkčních bloků. Druhá část se zabývá popisem jednotlivých funkčních bloků a jejich rolí v rámci celé síťové topologie. Bloky jsou dále rozděleny na jednotlivá zařízení a jsou popsány služby, které tato zařízení musí poskytovat. Třetí část DP se snaží zmapovat základní požadavky na služby, které jsou kladeny na dnešní síťové infrastruktury. Hlavní důraz je kladen na dostupnost všech nabízených služeb sítě. Jsou vyjmenovány jednotlivé protokoly druhé až třetí vrstvy OSI modelu, které zabezpečují stálou dostupnost sítě v případě selhání aktivních prvků. Čtvrtá část DP se věnuje popisu návrhu síťové topologie WAN. Pátá část obsahuje popis bezpečnostních rizik, která ohrožují dostupnost sítě, tak i popis útoků, které mají za cíl krádež identity uživatele. V šesté části DP jsou popsány programové nástroje pro zprávu sítí (Nagios, Cisco Security Device Manager) a programy, které simulují Cisco přepínače, směrovače (Dynamips & Dynagen, GNS3) a Cisco PIX firewall (PEMU). Sedmá kapitola se zabývá konkrétním návrhem rozsáhlé sítě s použitím principů, které byly zmíněny v předcházejících kapitolách. Navržená infrastruktura je dále realizována pomocí simulačních programů a tato virtuální síť dovoluje demonstrovat nastavení a chování všech popsaných protokolů a zařízení. V závěrečném shrnutí je nejdůležitější poznatek, že návrh a konfigurace rozsáhlé sítě a její realizace ve virtuálním prostředí je funkční a použitelná pro pokusné účely i pro studijní účely.

The Master’s thesis deals with logistics and resources monitoring area, which is inseparable part of every production oriented economic activity. It uses electronic monitoring systems for more effective dealing with stock records in a production company that has many stores. The monitoring utilizes modern technologies, that are burgeoning and finding its use in all branches of market.

This thesis deals with the exploration of possibilities of LAN analysis with the use of the hardware analyzer Finisar TGHs from the Finisar Corporation Company. As a monitored network was choosed the local computer network in the laboratory PA-249 at the Department of Telecommunications, which is located at the Faculty of Electrical Engineering and Communication, Brno University of Technology. All results acquired from the complex long-term monitoring of the choosed LAN network are described in this thesis. Further, the thesis is focused on the simulation and analysis of the model of this network that was created in the simulation environment Opnet Modeler. The data obtained from the real LAN monitoring were used as a basis of an operating simulation of the transmission abilities and features of the real LAN network. The last part of the thesis describes the verification of the transmission capabilities and characteristics of the real LAN. Verification was performed in Opnet Modeler, where the network has been analyzed in detail.

This Master’s thesis is dealt in the local area network security, cryptographic algorithms, particular attacks on computer networks a practical application these attacks in local area networks. To application particular attacks is used the Cain & Abel program. The detailed manual for this program is created from the results of these attacks. This manual contains the exhibits of usage particular program tools and the attack application exhibits. This manual considers consequences of particular attacks and summarises achieved results during work with tools too. Master thesis closely deals with one of the program tools called RSA SecureID Token Calculator. Authentication via hardware tokens is contained in this Master thesis. Thesis contains the way of authentication using RSA SecureID Token Calculator without physical owning of the hardware token. Cain & Abel program shows and interprets why cashed passwords in operation system are dangerous and it shows methods how attacker can reveal this passwords from the operation system memory. This Master thesis is focused on sniffing credentials and passwords in local area networks and it is focused on cryptographic algorithms cracking for username and passwords revealing.

This labor discusses with the possibilities of using a network connection devices in measurement technology from Agilent. It deals with the theoretical description of the different ways of measuring devices connected to computer networks and their use in laboratory teaching. Practical work is focused on creating automated utilities for selected tasks in the laboratory diagnosis of electrical materials in the software Agilent VEE Pro. The work is a detailed description of the labs in terms of setting and controlling the basic parameters created by the application. Installation and configuration of software and hardware communication tools are summarized in the brochure "How to handle a remote connection of measuring instruments over the Internet."