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 …