Automation of ICT-infrastructure link layer graph discovery for local internet service providers

The problem of automated Network link layer graph discovery is considered. A solution of the problem is complicated by the lack of standardized tools for device discovery and neighborhood notification. Therefore, the problem of new methods for the Network link layer graph development with the use of different non-specialized data sources is important. 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 was developed on the basis of the model. The algorithm uses data provided by CDP, LLDP, STP and ARP protocols, accumulated by network devices and retrieved from their MIBs with the use of SNMP. Testing of the Network graph building tools becomes very complicated because of the variety of link layer protocols and technologies. Experimental network environment built with the use of GNS3 network simulator was applied in the process of algorithm testing. Complex algorithm testing results obtained both in different experimental settings and in the real PetrSU network are presented.