Abstract
The questions related to the use of simulation to evaluate the effectiveness of information protection systems in local area networks. Developed a simulation model to determine the dependence of changes in the probability of breaking LANs over time on five different channels of communication and PC master server LAN. Using the established simulation model have been carried out computational experiments using the software package Matlab and performed statistical analysis of the results of experiments using a spreadsheet EXСEL. Analytical graphic dependences to determine the number of attacks blocked by time for one channel and for the entire system. The dependences obtained allow to determine the most vulnerable places in the computer information systems, to choose the most effective hardware and software to protect LANs. The developed technique will allow developers to provide the necessary assistance of local corporate computer networks in their design for a preliminary assessment of their effectiveness to protect the information.