What is Network

•Computers are connected in a network to exchange information or resources each other.
•Two or more computer connected through network media called computer network.
• Computer loaded with Linux Operating System can also be a part of network whether it is small or large network by its multitasking and multi user natures.

How to check IP of Linux System

#ifconfig

#ip addr

#ip addr show

#hostname –I

#/sbin/ifconfig

Network Layers

Network Manager

•NetworkManager can be used with the following types of connections: Ethernet, VLANs, Bridges, Bonds, Teams, Wi-Fi, mobile broadband .

•NetworkManager can configure network aliases, IP addresses, static routes, DNS information, and VPN connections, as well as many connection-specific parameters.

•Installing NetworkManager: is installed by default on Red Hat Enterprise Linux. If necessary, to ensure that it is, run the following command as the root user:

•The NetworkManager Daemon:

      #yum install NetworkManager
      #systemctl status NetworkManager
      # systemctl start NetworkManager
      # systemctl enable NetworkManager

NetworkManager nmtui:

•The NetworkManager text user interface (TUI) tool, nmtui, provides a text interface to configure networking by controlling NetworkManager.

•At time of writing, it is not installed along with NetworkManager by default.

•To install NetworkManager-tui, issue the following command as root:

     #yum install NetworkManager-tui

•To start nmtui, issue a command as follows:

    #nmtui

NetworkManager nmcli:

•The NetworkManager command line tool, nmcli, provides a command line way to configure networking by controlling NetworkManager.

•It is installed, along with NetworkManager, by default.

•nmcli is a command-line tool which is used for controlling NetworkManager.

• nmcli command can also be used to display network device status, create, edit, activate/deactivate, and delete network connections.

nmcli Examples:

•To check the device status using nmcli command.

     #nmcli dev status

•To check active connection on the device.

    #nmcli connection

•To check active connection on the device.

    #nmcli device list

•Show the version information version

     #nmcli –v

•To get the current hostname

    #nmcli general hostname

Running Network Script and Services:

•Systemctl start |stop|restart|status network

•Systemctl l enable |disable network

•Do not run directly any service using below command:

•/etc/init.d/servicename start|stop|restart|status

Network Configuration Path:

How to check & set Linux Hostname :

How to check Linux System Hostname:

•# hostname

•# hostname -s

•# hostname –f

•#hostnamectl

•#cat /etc/hostname

•# sysctl kernel.hostname

How to set Linux System Hostname:

# hostnamectl set-hostname newhostname