Automation of an Enterprise Network’s ICT-Infrastructure Link Layer Graph Construction

The structured description of enterprise networks' ICT-infrastructure (the Network) technical component is a crucial input for solution process of many network management tasks. Usually, a graph, where vertices are representing network devices and edges — links between them (according to the OSI model), can be used as such a description.

In this article we are considering the problem of the IEEE-802 based Networks link layer graph building automation. Lack of standardized tools for device discovery and neighborhood notification complicates this problem. Therefore using of non-specialized data sources is very common in search of information on device connections.

The article provides an overview of existing methods for solving the noted problem and also suggests a graph model for the link layer description considering the presence of a number of broadcast domains produced by VLANs. A new complex algorithm for building the link layer graph (including VLAN) had been developed on basis of the model. The algorithm uses data, accumulated by network nodes in the course of the functioning of CDP, LLDP, STP and ARP protocols, retrieved from MIBs of the devices using SNMP protocol.

Testing of the Network graph building tools becomes very complicated because of variety of protocols and technologies, used on link layer. For creation of experimental network environments authors use the GNS3 network simulator. The article concludes with results of complex algorithm testing as in experimental environment and in real PetrSU network.