The main feature of any network system is that its components are distributed in space and the relation between them is physically carried out by means of network connections (coax, twisted pair, fiber, etc.) and software through the mechanism of communications.

   Moreover, all control messages and data sent between objects distributed computing system (CS), are transmitted across a network connection in the form of packet exchange.

   Network systems are characterized by the fact that, along with the usual (local) attacks, carried out within a single computer system, they apply a specific kind of attack, due to the allocation of resources and information in space. This so-called network (or remote) attack.

   They are characterized, firstly, the fact that someone could be thousands of miles away from the attacked object, and, secondly, that the attack could not be subjected to a specific computer, and information spreads through network connections. With the development of local and global networks is remote attacks are leading both the number of attempts, and on the success of their application and, accordingly, the security of aircraft with in terms of opposition to a remote attack is of paramount importance.

   Specificity distributed CS is that if the local Sun were the most frequent threats of disclosure and integrity, in network systems, as will be shown below, in the first place comes the threat of denial of service.

   Under a remote attack we mean information damaging effects on distributed computer systems, software implemented on the communication channels. This definition encompasses both features of network systems - distributed computers and distributed information.

   Therefore, we will consider two subtypes of such attacks - a remote attacks on the infrastructure and network protocols and remote attacks on telecommunication services. The first advantage of vulnerabilities in network protocols and network infrastructure, and the second - the vulnerability of telecommunications services. In this case, a network infrastructure, we understand the existing system of organization of relations between objects and the network used in the network of service stations.