I got the chance to configure one of the old system of my friend running Windows 2000 and Ubuntu 7, (yes it’s not typo) and he wants to authenticate some of his old Ubuntu PCs to Windows AD. Here’s the tutorial for adding Ubuntu box in a Active Directory domain and to authenticate the users with AD

Needed software:
Windows 2000 Advanced Server (function as Domain Controller, AD)
Linux (Ubuntu 6,7)

Used terms:
AD.freelinuxtutorials.com –> AD Domain –> DC IP address
AD.freelinuxtutorials.com –> Kerberos Realm –> NTP server

Installation of KVM and Eve-NG

 Kernel-based Virtual Machine or KVM is an open source virtualization solution that can make your Linux Server as hypervisor. I will demonstrate also how to install Virtual Machine (VM), for this example I will install Eve-NG (Emulated Virtual Environment) which is used by Network Engineers or Security and DevOps professionals to emulate different network devices/platforms such as Cisco,Juniper, Arista, Linux and so much more, mainly for POC, testing and learning.

Tested in CentOS 7
See first if your server supports Virtualization

# lscpu | grep Virt
Virtualization: VT-x

Want to deploy Openstack and experience your own cloud platform the easier way? One way is to install Openstack via RDO Packstack*.
*Packstack is a utility that uses Puppet modules to deploy various parts of OpenStack . It is suitable for deploying both single node proof of concept  or more complex multi node installations.

Components used and tested in:
CentOS 7 Linux 3.10.0-693.el7.x86_64
Openstack Packstack (latest stable release, Pike)

Advisable to stop firewalld, NetworkManager and enable network

#service firewalld stop
#chkconfig firewalld off
#service NetworkManager stop
#chkconfig NetworkManager off
#service network start
#chkconfig network on

Sample Output:

It is meant to function as a staging or testing server where you can  do compatibility test  latest wordpress version on your existing sites, or try themes, plugins,widgets or practice your coding skills in css & php before deploying into your production, then using rpi is a good option.

Components used and tested working:

Raspberry Pi Model B , installed with Raspbian GNU/Linux 8 Jessie (Kernel armv6l Linux 4.9.35+)
nginx(1.6.2-5+deb8u5) (Web Server)
php5 (php5 5.6.33)
mysql 5.5 (ver.5.5.59-0+deb8u1) (Database Server)

Before start the actual installation, update rpi packages

pi@raspberrypi:~ $ sudo apt-get update; sudo apt-get upgrade

Some sample websites that you can use with curl to display your external public IP. As you know, especially if you are connected to a router, it will provide you private IP via the DHCP and it is NAT’ed. So using ‘ifconfig’, ‘ip addr show’, ‘hostname -I’ or via the GUI won’t show the public IP.

curl icanhazip.com
curl ifconfig.me
curl ipecho.net/plain ; echo
curl ident.me ; echo
curl checkip.amazonaws.com
curl bot.whatismyipaddress.com ;echo
curl myexternalip.com/raw
curl whatismyip.akamai.com ; echo
curl myip.dnsomatic.com;echo
curl -s ipinfo.io | jq .ip #need to install jq

Scenario: Multiple network interfaces in your server and each connected to different network and getting the IP via DHCP
Objective: Make all IP pingable and accessible remotely e.g. SSH
Solution: Configure Gateway Routing or setting up multiple default routes for each interfaces

Initially when you connect different links/network (regardless it’s in the same subnet or not) for each of the interfaces, it will end up only one interface is reachable. Why? Because by default, it can only have one default route or gateway on a system.

Example: 5 NIC in 1 Linux Server
Noted: Tested in Redhat based Linux (CentOS,Fedora). Assuming the IP dynamically assigned by the DHCP server:

After installing GNS3 or Graphical Network Simulator 3 in Ubuntu Linux, you can run it via the command “gns3” but it does not come with a default launcher or shortcut. To have a nice shortcut to place under your launcher bar or dock, here are the steps:

1. Go to /usr/share/applications folder

tux@freelinux:~$ cd /usr/share/applications

2. Create a filename with extension “desktop” , e.g. gns3.desktop . Configure the following desktop entries as per below. The contents are quite self-explanatory. Save and exit

tux@freelinux:/usr/share/applications$ sudo vi gns3.desktop

[Desktop Entry]
Comment=GNS3 Network Simulator

Spotify is considered the king of digital music streaming service that offers millions of songs.  There are 4 steps to install Spotify client in Debian-based Linux.

Tested in Ubuntu 16.04 LTS. Enjoy!

1.Add Spotify’s repository signing key to verify downloaded packages
sudo apt-key adv –keyserver hkp://keyserver.ubuntu.com:80 –recv-keys BBEBDCB318AD50EC6865090613B00F1FD2C19886

2. Add Spotify repository
echo deb http://repository.spotify.com stable non-free | sudo tee /etc/apt/sources.list.d/spotify.list

3. Check and update latest version
sudo apt-get update

4. Install the Spotify client
sudo apt-get install spotify-client

Run “spotify” in the command-line or find from the Applications

Sublime Text is one of the best text or code editor that you can have in Linux as it supports different programming languages and markup languages. There’s a list of features that you can check from the Sublime Text official website, one of my favorites is the python-based plugin API and “Goto Anything” feature.
The only downfall I find is Sublime Text may be downloaded and evaluated for free, however a license must be purchased for continued use.

Installing Sublime Text ver.3 in Ubuntu 16.04 LTS can be done in just 3 steps. As it is not available in Ubuntu Software Center, need to add first the repository before installing it.

Installing a graphical network simulator GNS3 is quite easy for Ubuntu based distribution for 64-bit systems. Tested using Ubuntu 16.04.

sudo add-apt-repository ppa:gns3/ppa
sudo apt-get update
sudo apt-get install gns3-gui

few packages will be installed aside from the gns3-gui , gns3-server


Type “gns3” in command line to launch the application. Enjoy!

tux@freelinux:~$ sudo add-apt-repository ppa:gns3/ppa


About FLT

This site is dedicated to everyone who likes to learn and explore the beautiful world of Linux. If you have comments and suggestions, please feel free to email at freelinuxtutorials@gmail.com. I am happy to serve and share things esp. that is free and enjoyable as Linux.