Gert Pfeifer

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The main functionality of the Domain Name System (DNS) is to translate symbolic names into IP addresses. Due to the criticality of DNS for the proper functioning of the Inter-net, many improvements have been proposed for DNS in terms of security and dependability. However, the current secure DNS (DNSSEC) standard has still several problems that need further(More)
Structured P2P networks are a promising alternative for engineering new distributed services and for replacing existing distributed services like DNS. Providing competitive performance with traditional distributed services is however very difficult because existing services like DNS are highly tuned using a combination of caching and localized(More)
DNS is one of the most important components of the Internet infrastructure. Unfortunately, it is known to be difficult to implement, and available implementations are difficult to configure correctly. DNS performance and availability often suffer from poor configuration which leads to unavailability or erroneous behavior of distributed systems that depend(More)
Building realistic Internet topologies is an important step towards predicting the behavior of new distributed applications and protocols.We are creating topologies that predict the distances between identifiable nodes in the Internet as it is today.These nodes are not anonymous average Internet nodes, but are known by name and network address.We are using(More)
The main functionality of the Domain Name System (DNS) is to translate symbolic names into IP addresses. Since there is a growing demand for trustworthiness in the Internet many research articles consider DNS security issues. The reason is that DNS is a vital service for nearly all distributed applications based on the TCP/IP protocol suite. This article(More)
Simulation of distributed applications and overlay networks is challenging. Often the results generated in simulation do not match experimental results. Distributed testbeds like Planet-Lab help to bridge the gap, but they do not offer enough nodes to do an Internet scale evaluation. In this paper we use a tool called TopDNS for generating realistic(More)
This article examines the supporting mathematical methods for modeling and simulation of computer networks. The authors discuss approaches to composition of analysis-able mathematical models for computer networks. The DFG (Dichromatic Functional Graph) is investigated as a relevant theoretical basis. Furthermore, the approaches to modeling of elements and(More)
ii iii Abstract In this thesis I describe my research activities and results of the last 4 years. I also provide an outlook and guidelines on how to proceed with our project, that we named SEDNS-Security-Enhanced Domain Name System. This project's ambitions are to complement DNS, the Domain Name System, in a way that allows us to keep using it in the(More)
The Domain Name System (DNS) has been the naming service of the Internet for more than 20 years. It is the foundation of virtually all other distributed service. The deficiencies of DNS with respect to performance, availability,a nd reliability are well known. We want to systematically improve DNS by (1) measuring DNS performance, (2) evaluating past(More)
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