In this article, we will see 20 dig command examples in Linux. dig, also known as domain internet groper is a free and open source tool for querying the domain name system(DNS). It is very commonly used for performing DNS lookups to retrieve various DNS records such as A (address), MX (mail exchange), NS (name ... Read more

In this article, we will see how to install whois utility on Ubuntu 20.04 based systems. If you are looking for the registration details of the domain, including the owner's name (or organization's name), contact information, registration and expiration dates, and more then there is no better tool than whois utility. All of need to ... Read more

In this article, we will see 13 Linux commands/shell scripts to check if you are connected to internet. Many times when you are unsure about the availability of internet connection in your linux system, you might want to run a quick test to check and confirm. You can do this by using few tools and ... Read more

In this article, we will see how to install nmap on Ubuntu 22.04. Nmap, also known as network mapper is a free and very powerful open source network discovery and security auditing tool used for performing various types of tasks including discovering devices on a network, identifying host, services, ports, operating systems and much more. ... Read more

In this article, we will see how to install fping on Ubuntu 22.04. fping is a free and open source utility used for sending ICMP echo requests to all the hosts in the network. It works very similar to ping utility but comparatively it is very efficient and faster with multiple hosts. fping send ICMP ... Read more

In this article, we will see how to install arping on Ubuntu 22.04. arping is a free and open source utility that broadcasts arp packets to all the systems in the network to detect ethernet and IP address of the target. It also displays the time elapsed between arp request and arp reply. In case, ... Read more

In this article, we will see how to install dependent packages on Ubuntu/Debian using gdebi. Many times, you might have observed that for some of the applications it is not possible to download and install them from default Ubuntu repo, you will most probably have to download the debian package for that from its official ... Read more

In this article, we will see how to install VirtualBox on Ubuntu 20.04 LTS. Virtualbox is an extremely powerful, feature rich, free and open source virtualization software available to use in almost all the famous platforms in both enterprise as well as for home use purposes. It supports a huge list of guest operating systems ... Read more

It is often very confusing when you notice removed or uninstalled debian packages still shows in dpkg list. This usually happens when you remove the debian packages through sudo apt remove <package_name> command and after removal when you check the list of installed packages through dpkg -l command then the removed packages still be showing ... Read more

In this article, we will see how to solve "The repository 'http://pkg.jenkins.io/debian-stable binary/ Release' is not signed" error. You might have observed this error during installation of Jenkins in your Linux based servers. This error precisely comes when you try to run either sudo apt update or sudo apt-get update command on Ubuntu/Debian based systems ... Read more