bash: ifconfig: command not found debian centos ubuntu rhel

This article will be helpful for Ubuntu, CentOS, RHEL, Debian, Raspbian OS users.

ifconfig is a very commonly used command to find the ipaddress of a linux machine. Sometimes we may get an error like

bash: ifconfig: command not found

The reason for this can be because of one of the following reasons.

  • The ifconfig command is not available in the system.
    • In case of this issue, we have to install the net-tools package
  • The ifconfig script is not available in the PATH
    • In this case, we have to try executing /sbin/ifconfig command

In these cases, we can get the ip address details by using another command. We don’t have to install any additional package for issuing the following command

ip addr

If the net-tools package is missing in the system, we can enable ifconfig by installing the package. The command to install the package is given below.

For Ubuntu, Raspbian, Debian OS use the following command

sudo apt-get install net-tools

For RHEL / CentOS users, use the following command

sudo yum install net-tools

Now try ifconfig in the commandline and you will be able to see the ip address details.

 

How to install Chromium browser in Raspberry Pi debian ?

By default, there will not be any browser included in the debian OS for raspberry Pi. Chromium is one of the best browser for raspberry pi. We can install chromium browser in raspberry pi debian OS using the following simple steps,

sudo apt-get update
sudo apt-get install chromium-browser

Now after doing this, check the home icon in raspberry pi and you will be able to see an additional option “Internet” and on expanding, you can see chromium browser. All set šŸ™‚

Can’t open config file: /usr/local/ssl/openssl.cnf on Windows

I faced the above issue while trying to use openssl in window. I have downloaded openssl and extracted in my windows server. After that I tried executing the following command.

openssl.exe genrsa -out subdomain.mydomain.com.key 2048

Solution:

Open Powershell

set OPENSSL_CONF=c:\[PATH TO YOUR OPENSSL DIRECTORY]\bin\openssl.cnf

Now execute the openssl command to generate the certificate. It will work without any issues. I hope this is helpful.

How to connect a CentOS computer to Internet using USB Wifi Adapter ?

I have an old desktop computer with CentOS 7 operating system installed without GUI. I wanted to connect to internet using a USB wifi adapter. My internet router was located in a different room and LAN cable was not available with me. So I used netgear USB wifi adapter for establishing the internet connection. This post is about troubleshooting and fixing the connectivity issue.

The model that I have used is Netgear WNA3100M Wireless-N300 USB Mini Adapter. The picture is shown below.

wifi_network_adapter

Netgear WNA3100M

I checked the network interfaces and ip address using ifconfig command. It listed an interface named wlp18s0b1.Ā But no ip address was assigned.

I tried ifup command. But it gave me an error as follows.

ifup wlp18s0b1

/sbin/ifup: configuration for wlp18s0b1 not found.
Usage: ifup 

Then I tried listing the USB interfaces using lsusb command and it listed the network adapter usb device. This means that the device is getting detected.

The next steps that I tried are using the nmcli command.

The following command will list all the available Wifi connection profiles.

nmcli connection show

To connect to a wifi network, use the below command. You have to pass your wifi ssid and password as shown below as arguments.

nmcli dev wifi connect your-wifi-ssid password wifi-password

My desktop got connected to the internet after triggering the above command. After this, every time I start my computer, if the desktop is not automatically connected to the internet, I issue the following commands.

nmcli connection show

nmcli connection up your-wifi-connection

This solution helped me. Hope this will help someone else also :).

Configure Network in CentOS / RHEL from command line

How many of you are aware of a text user interface for network configuration ?. A tool called NMTUI (Network Manager Text User Interface) is available in CentOS and Redhat systems. You can simply open this by typing nmtui in the command line.

If this command is not available, you have to install theĀ NetworkManager-tuiĀ package.

yum installĀ NetworkManager-tui

If you type nmtui command in command line, the following console will open up. You can configure the network configurations in the opened console. You can

nmtui

nmtui

Disable Sleep mode in CentOS7/RHEL7 laptop on lid close

The following tip will help you to disable the powersaving or sleep mode behavior of your CentOS or RHEL laptop or desktop. If GUI is present, the following steps will help.

Applications => Utilities => Tweak Tool => Shell => Don't suspend on lid close => ON

But if GUI is not installed, then the only option is to disable this from the commandline. It is very easy, don’t worry. Who cares about the GUI in Linux. ? šŸ™‚ (I love the black screen)

OpenĀ /etc/systemd/logind.conf, then make edit in the following configuration. By default, the value of this config will be suspend

HandleLidSwitch=ignore

man logind.conf will provide the complete details about this configuration file. Hope this tip helps.