This diploma thesis focuses on the preparation of an operating system, a simulation environment and the creation of two laboratory exercises explaining network technologies. In the theoretical part protocols DHCP, FTP, TFTP, HTTP, and NAT service are described. The practical part focuses on the installation of ns-3 and GNS3 programmes and their utilization and settings on OS Ubuntu 18.10. Moreover, it deals with the preparation of laboratory exercises created in the simulation programmes mentioned above together with tutorials, self-check questions and HTTP server in the Python programming language.

The main object of this thesis was to design a computer network for small and medium companies which will be made among others from network server providing simple network control. The next task was to provide internet connection to subscribers of local area network, their security and access to common services. There had been discussed the choice of distribution of Linux operation system with regarding to demanded services, stability and long lasting operation in theoretical part. One part of the work is a theoretic preliminary to separate services, to the purpose of their using and to their weaknesses. The practical part deals with an installation and configuration of Debian operating system, launching the base services and the setting of selected monitoring programs.

This thesis is focused on crypto-module RCM 3700, which is used for encrypted data transmission. Following work analyses basic network protocols and some sort of attacks in Ethernet network. The main goal of these attacks is to collect information and services about the device and to analyze transmitted data. Based on these information attacks can be done more precisely than without them. The main target of these attacks is the denial of particulary service or data abuse. Furthermore, in the diploma thesis configuration of router CISCO 2801 is applied in order to improve the LAN security. The deveploment board, which includes reset function, supplied circuit and interface for RS 232, was designed for crypto-module RCM 3700.

Diploma thesis deals with four laboratory tasks in simulation environment GNS3. Designed tasks are primarily focused on comparison of IPv4 and IPv6 protocols. In the first task the subject is concerned about OSPFv2 and OSPFv3 routing protocols. Next themes are transit techniques like NAT-PT and tunneling like GRE and 6to4. The second task is focused on configuration of routing protocols like EIGRP and EIGRPv6. Next sections are concerned about DHCP and ICMP protocols within IPv4 and IPv6 protocol suits. The third task is primarily focused on security relations of protocol suite IPv6. It contains OSPFv3 authentication, access lists and Cisco stateful IOS firewall. Content of the fourth task is protocol MPLS. First part of this task is concerned about basic configuration of this protocol and second part is focused on MPLS within IPv6 environment. All tasks contain test questions and individual part task.

The work deals with the measurement of electrical quantities, distribution of data across the Ethernet network into the Internet and intelligent selection of the required values to be transmitted and stored on a central node. The work describes the communication protocols in scale that is necessary for implementation, discussed the requirements for computational resources and microcontroller control is proposed by flowcharts. Attached are source codes in C programming language for microcontroller and PHP scripts for storing and presenting data on Web server.

Diese Arbeit beschaeftigt sich mit Methoden fuer die Authentifizierung, Autorisation und das Accounting (AAA) im Zusammenhang mit dynamischen Hostkonfigurationsprotokollen auf Basis von IPv6. Die zustandlose (autom. Konfig.) und die zustandsgebundene Adresskonfiguration (DHCP) von IPv6 wird auf moegliche AAA Ansatzpunkte untersucht. Es wird eine DHCPv6 Beispielimplementation fuer Linux erstellt.

Every corporation using IT technologies needs a good and carefully secured network design. The IT security is a key factor of a normal functional of the whole corporation and all its sections. There different methods and concepts for providing different level of IT security. Some of them are very important and should be implemented in every corporate network. There are a lot of services providing inside and outside the corporation network. Increasing the number of services like web services, mail services, file services and other, the number of eventual security issues is rising. The security methods of each of provided services are different and it is required a professional with deep knowledge about this service functionality if it is needed to be good applied. Operation system and application hardering are methods which are not so hard for applying, like configuring proxy server or firewalls, but they could increase the security drastic. In a combination with simple configured security devices, the results could be very impressive. Choosing the right methodology and framework of designing a secured network is important part of entire process. With the right methodology designing could be easier and more effective.

<p>The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption.</p> / <p>Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.</p>

The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption. / Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.

Die vorliegende Arbeit entwickelt und implementiert ein System für die Bereitstellung von Internet-Diensten an öffentlichen Orten. Besonderer Wert wurde auf eine einfache Handhabung für den Nutzer, eine breite Unterstützung von Klienten und ein breites Spektrum möglicher Privilegien (von der vollen Internetkonnektivität bis zu einer Art Infoterminalstatus) gelegt.