Research and Implement of an Algorithm for Physical Topology Automatic Discovery in Switched Ethernet

AbstractIn this paper, a novel practical algorithmic solution for automatic discovering the physical topology of switched Ethernet was proposed. Our algorithm collects standard SNMP MIB information that is widely supported in modern IP networks and then builds the physical topology of the active network. We described the relative definitions, system model and proved the correctness of the algorithm. Practically, the algorithm was implemented in our visualization network monitoring system. We also presented the main steps of the algorithm, core codes and running results on the lab network. The experimental results clearly validate our approach, demonstrating that our algorithm is simple and effective which can discover the accurate up-to-date physical network topology

Development of a distributed firewall administration tool

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2008Includes bibliographical references (leaves: 58-61)Text in English; Abstract: Turkish and Englishxi, 61 leavesToday firewalls not only guard internal computer networks but also individual personal computers against malicious and unauthorized accesses from outside. The purpose of this study is to create architecture and its corresponding application to manage distributed firewalls running on Microsoft Windows platform. Distributed Firewall Administration is about creating a management center for a network composed of the firewalls running on Microsoft Windows platform. Main important part of this work is to determine distributed firewall network topology with breadth-first search and depth-first search algorithms.The Microsoft Windows Firewall API makes it possible to programmatically manage the features of firewalls running on windows platform by allowing applications to create, enable and disable firewall exceptions. This study used the Windows Firewall API to manage the features of it. This API is only reachable using C/C++ low level programming languages.Distributed Firewall Administration Tool (DFAT) can add, modify or delete rules on the end-user firewall rule set, these rules stored on the database. This tool works on a distributed environment, there is a parent child relationship between firewalls. Parent firewalls have right to manage its child firewall.s rule set. Firewalls introduce themselves to each other with broadcast method

Mobile IP: state of the art report

Due to roaming, a mobile device may change its network attachment each time it moves to a new link. This might cause a disruption for the Internet data packets that have to reach the mobile node. Mobile IP is a protocol, developed by the Mobile IP Internet Engineering Task Force (IETF) working group, that is able to inform the network about this change in network attachment such that the Internet data packets will be delivered in a seamless way to the new point of attachment. This document presents current developments and research activities in the Mobile IP area

Efficient Routing for Wireless Mesh Networks Using a Backup Path

Wireless Mesh Network (WMN) has a proven record in providing viable solutions for some of the fundamental issues in wireless networks such as capacity and range limitations. WMN infrastructure includes clusters of Mobile Ad-Hoc Networks (MANETs) connected through a fixed backbone of mesh routers. The mesh network can be constrained severely due to various reasons, which could result in performance degradation such as a drop in throughput or long delays. Solutions to this problem often focus on multipath or multichannel extensions to the existing ad- hoc routing protocols. In this paper, we propose a novel solution by introducing an alternative path to the mesh backbone that traverses the MANET part of the WMN. The new routing solution allows the Mobile Nodes (MNs) to establish direct communication among peers without going through the backbone. The proposed alternative ad-hoc path is used only when the mesh backbone is severely constrained. We also propose, for the first time in WMNs, using MNs with two interfaces, one used in the mesh backbone communication and the other engaged in the ad-hoc network. A scheme is presented for making the MN aware of link quality measures by providing throughput values to the AODV protocol. We use piggybacking on route reply messages in AODV to avoid incurring additional costs. We implemented our solution in an OPNET simulator and evaluated its performance under a variety of conditions. Simulation results show that the alternative ad-hoc path provides higher throughput and lower delays. Delay analysis show that the throughput improvement does not impose additional costs

A Graph Theoretic Perspective on Internet Topology Mapping

Understanding the topological characteristics of the Internet is an important research issue as the Internet grows with no central authority. Internet topology mapping studies help better understand the structure and dynamics of the Internet backbone. Knowing the underlying topology, researchers can better develop new protocols and services or fine-tune existing ones. Subnet-level Internet topology measurement studies involve three stages: topology collection, topology construction, and topology analysis. Each of these stages contains challenging tasks, especially when large-scale backbone topologies of millions of nodes are studied. In this dissertation, I first discuss issues in subnet-level Internet topology mapping and review state-of-the-art approaches to handle them. I propose a novel graph data indexing approach to to efficiently process large scale topology data. I then conduct an experimental study to understand how the responsiveness of routers has changed over the last decade and how it differs based on the probing mechanism. I then propose an efficient unresponsive resolution approach by incorporating our structural graph indexing technique. Finally, I introduce Cheleby, an integrated Internet topology mapping system. Cheleby first dynamically probes observed subnetworks using a team of PlanetLab nodes around the world to obtain comprehensive backbone topologies. Then, it utilizes efficient algorithms to resolve subnets, IP aliases, and unresponsive routers in the collected data sets to construct comprehensive subnet-level topologies. Sample topologies are provided at http://cheleby.cse.unr.edu