Routers Let’s begin with routers. Our aim here is to give you a firm understanding of the basic functions of routers, so you’ll use this knowledge for more complex hacking techniques and tools. A quick overview of the fundamentals: a router’s main function is to direct packets (layer 3 traffic) to the appropriate location based … Read more
Domain Name System (DNS) and its ability to translate names to IP addresses and back. The DNS that you may already be aware of, even if you don’t actively think about it, is the one used to translate names to IPs on the Internet. DNS is incredibly powerful and easy to use, but at the … Read more
Ports allow computers to send data out the door while simultaneously identifying that data by category. What this means is each of the common ports you use is associated with a particular protocol or particular application. For example, sending data from port 21 signifies to the receiving system that the traffic received is an FTP … Read more
Understanding hexadecimal and binary conversion is an important skill to have for the exam. In the real world, for most network administrators conversion is done either by a calculator or is not needed, but as an ethical hacker, you have opportunities to apply the basic conversions to something useful. See Table for the basic conversion … Read more
Subnetting is the logical breakdown of a network address space into progressively smaller subnetworks. That’s it. Stop thinking and take it for what it is! Now, as you break down your address space into smaller subnetworks, you determine the numbers of network bits and host bits by the requirements of your network. Network bits and … Read more
Complementary to the OSI model is the TCP/IP protocol suite. TCP/IP is not necessarily a direct offshoot, but it’s a progressive step from the standard OSI version of traffic flow. Each layer of the TCP/IP suite maps to one or several layers of the OSI model. The TCP/ IP suite is important for protocol reference … Read more
History of email and When the first email sent Electronic mail (email or e-mail) is a method of exchanging messages (“mail”) between people using electronic devices. Email entered limited use in the 1960s, but users could only send to users of the same computer, and some early email systems required the author and the recipient … Read more
No network discussion or network device explanation would be complete without a brief overview of the Open Systems Interconnection (OSI) model. Although this model may seem overly complex, it does have value in our later discussions of attacks, defenses, and infrastructure, as you will see. The OSI model is a general framework that enables network … Read more
Network topologies represent the physical side of the network, and they form part of the foundation of our overall system. Before we explore too far, the first thing you need to understand is that you must consider two opposing yet related concepts in this article: the physical layout of the network and the logical layout … Read more
`An important part of your toolkit as an ethical hacker will be the information gathered from vulnerability research. This process involves searching for and uncovering vulnerabilities in a system and determining their nature. Additionally, the research seeks to classify each vulnerability as high, medium, or low. You or other security personnel can use this research … Read more