Edinburgh Napier University

  Knowledge of network topologies is invaluable to system administrators regardless of the size of an enterprise. Yet this information is time consuming to collect, and even more so to be processed into easily consumable formats (i.e. visual maps). This is especially so when the culture within which administrators operate is more concerned with operational stability and continuity as deliverables rather than documentation and analysis. The time-cost of documentation impinges upon its own production. This continues to be the case although documentation is of increasing importance to nontechnical personnel in enterprises, and as a compliment/supplement to network management systems.

This thesis puts forth a framework to largely automate the process of documenting network topologies. The framework is based on issues raised in recent research concerning the needs of IT administrators, and network discovery methods. An application is also described serving as a proof-of-concept for the central elements of the framework. This application was realized in the Microsoft Visual C# 2005 Express Edition programming environment using the C#.NET language. The compiled result is supported by the .NET Framework 2.0 runtime environment. The application provides for an administrator to control, through a graphical interface, the sequence of discovering a network and outputting visual documentation. For testing, Cisco Systems routers and switches, along with a Microsoft Windows-based laptop, were used to construct a mock network. Measurements of the performance of the application were recorded against the mock network in order to compare it to other methods of network discovery.

Central to the application's implementation is a recognition that networks are more likely than not to be heterogeneous. That is, they will be comprised of equipment from more than a one vendor. This assumption focused the choices about the framework design and concept implementation toward open standard technologies. Namely, SNMP was selected for discovery and data gathering. XML is utilized for data storage. Data processing and document production is handled by XSL. Built around these technologies, the application successfully executed its design. It was able to query network devices and receive information from them about their configuration. It next stored that information in an XML document. Lastly, with no change to the source data, HTML and PDF documents were produced demonstrating details of the network. The work of this thesis finds that the open standard tools employed are both appropriate for, and capable of, automatically producing network documentation. Compared to some alternate tools, they are shown to be more capable in terms of speed, and more appropriate for learning about multiple layers of a network. The solution is also judged to be widely applicable to networks, and highly adaptable in the face of changing network environments. The choices of tools for the implementation were all largely foreign to the author. Apart from the prima face achievements, programming skills were significantly stretched, understanding of SNMP architecture was improved, and the basics of these XML languages was gained: XSLT, XPath, and XSL-FO.