Penetration testing course: 0x02.3.2 Network software – OSI and TCP/IP reference models






The first computer networks were designed with the hardware as the main concern and the software as an afterthought. This strategy no longer works. Network software is now highly structured. In the following sections we examine the software structuring technique in some detail. Protocol Hierarchies To reduce their design complexity, most networks are organized as a stack of layers or …






Penetration testing course: 0x02.3.1 Network hardware






Broadly speaking, there are two types of transmission technology that are in widespread use: broadcast links and point-to-point links. Point-to-point links connect individual pairs of machines. To go from the source to the destination on a network made up of point-to-point links, short messages, called packets in certain contexts, may have to first visit one or more intermediate machines. Often …






Penetration testing course: 0x02.3 Introduction to Computer Networks






“Humans are social animals” like Aristotle said and as such they need to communicate with each other. At the beginning there was only oral (verbal) and written communication, then thanks to the evolution of electronics and telecommunication systems humans were able to communicate with each other remotely by broadcasting messages via electrical or wireless signals. We’ve seen the introduction of …