Many administrators on Linux have become used to using the ifconfig command in order to display and set IP addresses on Linux hosts. Although the ifconfig command is still valid, it's marked as obsolete in favor of the ip command. For Microsoft Windows administrators who move to Linux, the use of ifconfig becomes the obvious choice. As ipconfig closely resembles the Windows command line, I encourage you to learn the ongoing ip command and all that it has to offer. Using either the ifconfig or ip command on RHEL 7 will also introduce new, consistent device names. This may come as a little shock to those used to /dev/eth0.

Finally, we will look at something very new to RHEL using the hostnamectl command. This can be used to set the hostname for the current session and persistently in a single shot, rather than using the hostname command and editing the /etc/hostname file.

The NetworkManager service has been a part of RHEL since version 6 and in its simplest form allows users to configure network configuration settings (such as joining Wi-Fi networks). Of course, this is really necessary when we consider laptop users with a Fedora or an RHEL laptop. This service extends well beyond the GUI and to server products installed with or without the X Server environment.

The NetworkManager service that ships with RHEL 7 is a dynamic network control and configuration daemon to keep network interfaces active while they remain available. As we have seen, the NetworkManager service not only maintains support for the traditional ifcfg- file type, but also extends this support to additional profiles. In this way, we can easily have a static IP address configuration for your laptop for different offices that you may visit, rather than relying on DHCP on each site.

Configuration of the NetworkManager service can be maintained via...

If you are using RHEL, CentOS, or Fedora on a graphical environment, then with the GNOME control center, we can interact with the NetworkManger service. We can also access network settings from the notifications area icon. This can be seen in the following screenshot on the RHEL 7.1 system:

To access the same, but through the control center, we can use the SUPER key. In the search dialog box, we will enter control network, as seen in the following screenshot:

Once we have accessed Network Settings, it's possible to simply disable all wireless interfaces with the traditional Airplane Mode. In this way, you can be assured of not plummeting to your certain death during takeoff and landing and still enjoy your game of Candy Crush Saga.

On the left-hand side panel, we can view the current known interfaces and the Network proxy settings. Here, we can add web proxies if required. On the RHEL 7.1 system we are using in this book, we...

More useful for mobile systems, such as laptop devices and tablets, we may configure profiles to easily load network configuration information specific to the location where you use the device. For example, if you are using a laptop at home, you may have a specific static IP address set, whereas when at work, you may have a DHCP-assigned address. Profiles can handle this situation easily and effortlessly.

Using the Add Profile button from the Network Settings control center, we are presented with the New Profile dialog box. From the left-side panel, we can select an option from the following given options:

We will create a new profile for DHCP for when at home; if you remember, we set a static IPv4 address earlier in the section using the traditional ifcfg- script located in the /etc/sysconfig/network-scripts directory. We will retain this setting and additionally allow ourselves to switch from the static address to DHCP...