nslookup is a network administration command-line tool available for many computer operating systems. It is used for querying the Domain Name System (DNS) to obtain domain name or IP address mapping information .- Wiki
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Networking related articles and tutorials
Understanding DNS – Beginners Guide to DNS
DNS (Domain Name System) is one of the most important technologies/services on the internet, as without it the Internet would be very difficult to use. DNS provides a name to number (IP address) mapping or translation, allowing internet users to use, easy to remember names, and not numbers to access resources on a network and the Internet.
Continue readingTCP/IP Ports and Sockets Explained
On a TCP/IP network every device must have an IP address. The IP address identifies the device e.g. computer. However an IP address alone is not sufficient for running network applications, as a computer can run multiple applications and/or services. Just as the IP address identifies the computer, The network port identifies the application or service running on the computer. The use of ports allow computers/devices to run multiple services/applications. The diagram below shows a computer to computer connection and identifies the IP addresses and ports.
Continue readingThe TCP/IP Model and Protocol Suite Explained for Beginners
Any one starting to learn about computer networking will be faced with learning about the OSI and TCP/IP networking models, and the TCP/IP protocol suite. In this tutorial we will look at networking protocol models, and explain how and why they are structured into layers. We will then look at the most common protocol suite, the TCP/IP protocol suite and the 4 layer model.
Continue readingBinary Numbers Explained – Beginners Guide
In my experience of teaching networking many students struggle with IP addresses because they lack an basic understanding of binary numbers. An understanding of binary numbers,the binary system, and how to convert between binary and decimal is essential for anyone involved in computers, coding, and networking.
Continue readingUnderstanding and Using The Hosts File-Beginners Guide
What is the hosts file? and What is it used for?– The hosts file performs a name to IP address mapping and was used on early computer networks for name resolution before DNS was developed. The hosts file is still present on computer systems (windows,Linux, MAC), tablets (e.g. android) etc and can be very useful for testing purposes. The hosts file is a simple text file that can be edited with a text editor like notepad. However it is important to note the hosts file doesn’t have a file extension like .txt.
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