Media Access Control

As the chapter describes the existing risks and threats in nets without wire, showing the vulnerable points, as much in the logical part as in protocols WEP and WAP, and also in the physical part that generally is left of side for the administrators more it is a crucial point in the development of one politics of solid security. In the third chapter used techniques and tools in such a way for protection as for a possible attack are mentioned. Programs are cited as the Netstumbler, that makes the analysis of traffic in a net without wire being able to identify valuable information for an attack, as the name of the net, the use of criptografia, MAC (Media Access Control) of customers, MAC of Access Point (AP) enter others. In the room and last chapter the main methods used for protection are described, as configurations of the concentrator, correct configuration of the 13 equipment customers, ways for criptografia application and generation of keys, in end, describes tools and procedures used for become a net without wire more the possible protege. 14 1 COMPUTER NETWORKS AND the STACK OF PROTOCOL TCP/IP According to Souza, (2000, p.12), computer networks are a set of devices, interconnected, capable to change information and to share resources. Generally these devices are hosts, printers or any another device capable to change given with the others we of the net. The interconnection of that if it speaks is the way of linking between these devices, that can be by means of coaxial handles, handles of tressed pairs, same optic fiber or the connection without wire, wireless.

With the computer networks the implantation of distributed systems of computation became possible. distributed systems use the net to change control information and with this it is capable to establish more flexible services of what the centered systems. It is common to classify the nets for its area of geographic abrangncia: local nets of computers also called LANs (Local Networks Area) enclose lesser areas and they do not exceed few kilometers, generally they are of one same organization and they work in high speed.