Network administrators use tcpdump to analyze traffic in Linux systems. Learn how to install and use tcpdump, as well as examine the results of captured traffic. tcpdump : Linux Network Sniffer Tool Protocol analyzers, also known as packet sniffers, capture network data for display or use by administrators. The captures include transport layer content, application layer … Read more
Check the hardware. When you’re beginning the troubleshooting process, check all your hardware to make sure it’s connected properly, turned on, and working. If a cord has come loose or somebody has switched off an important router, this could be the problem behind your networking issues. There’s no point in going through the process of … 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
Web server products range from extremely simple and lightweight software which does little more than serve up static pages, to highly complex application platforms that can handle a large variety of tasks. Historically, web server software has been subject to a wide range of serious security vulnerabilities, which have resulted in arbitrary code execution, file … Read more
we use the public Internet, a specific computer network (and one which probably most readers have used), as our principle vehicle for discussing computer networking protocols. But what is the Internet? We would like to give you a one-sentence definition of the Internet, a definition that you can take home and share with your family … Read more
Now that we’ve got a bit of a feel for what the “Internet” is, let’s consider another important word is the title of this book: “protocol.” What is a protocol? What does a protocol do? How would you recognize a protocol if you met one? A Human Analogy It is probably easiest to understand the … Read more
The Institute of Electrical and Electronics Engineers (IEEE) created the 802.11b Standard to provide a secure architecture for communicating with networking devices over an air medium but the standard has fallen short in providing a secure criterion. The 802.11b Standard has left many doors open for hackers to exploit these shortcomings and the goal of … Read more
Almost left half of the Internet users across the globe use ADSL routers/modems to connect to the Internet. However, most of them are unaware of the fact that it has a serious vulnerability in it which can easily be exploited by anyone with a basic knowledge of computer. In this post, I will show you how to hack an Ethernet … Read more
Introduction to Computer Networks Data Communication:When we communicate, we are sharing information. This sharing can be local or remote. Between individuals, local communication usually occurs face to face, whileremote communication takes place over distance. Components:A data communications system has five components. 1. Message. The message is the information (data) to be communicated. Popularforms of information … Read more