The paper describes the problems of information security of internet services when subjected to a distributed network attack. Describes the multi-agent model of attack. A system software simulated attack to study its properties in real time. The analysis of simulation results. An approach to maintain server stability under high load. Described hike proposed to implement on the basis of mechanisms of method "flood-gate".

Keywords: simulation, multagentnye systems, network threats, DDoS-attack, JADE, the stability of network services