Welcome to Learning RHEL Networking. My name is Andrew Mallett and I will offer you expert guidance and tuition that will provide you with the skills to tame this powerful and popular Linux distribution. We will work with Red Hat Enterprise Linux 7.1. This latest release offers many improvements and is more likely to be the next version. The movement to the new system, the service management of systemd and the ecosystem that spawns from it offers so much new for administrators to absorb.
Writing about an Enterprise Linux distribution is important as we see the increase in the number of organizations deploying Linux. As a result, we require knowledgeable professionals to manage these systems. The Linux Foundation with Dice, a specialist recruitment company, surveyed many large organizations and found the following results:
93 percent of the organizations polled were looking to employ Linux professionals
91 percent of hiring managers reported that they found it difficult to find skilled Linux administrators
As a side note to this, it was additionally noted that salaries for Linux professionals had increased by 9 percent during the last 12 months.
With such confidence in Linux coming from so many organizations, the focus of this book has to be commercially driven for me and you. We want you to be able to improve your career prospects as well as your Linux knowledge.
Enterprise Linux distributions, such as CentOS, Red Hat, Debian, and SUSE Enterprise Linux, do not deploy the latest and greatest bleeding-edge technology that you may find on home or enthusiast-oriented distributions, such as Fedora or openSUSE. Rather, they allow these to be development platforms to hone and perfect the software before migrating it to an enterprise a few months or even years later. Enterprise Linux has to be dependable, reliable, resilient, and supportable by the organization deploying it and the backend support coming from the community or paid support teams. By definition, the latest in software development does not lend itself well to this; these are the latest development, and knowledge of these developments and best practices will take time to evolve and develop.
Although the book will focus on RHEL, you may equally use Fedora 21 or CentOS; either of these releases will be able to provide you with a compatible platform, where we can work through many examples that are provided in the book.
Chapter 1, Introducing Enterprise Linux 7, helps you understand how enterprise-level Linux differs from other bleeding-edge distributions and the relationship between Red Hat, CentOS, and Fedora. This short chapter gives you a great understanding of RHEL and helps you learn RHEL 7 on your choice of platform.
Chapter 2, Configuring Network Settings, discusses how to configure your network settings and how Red Hat allows you to set the IP address configuration on your host.
Chapter 3, Configuring Key Network Services, helps your RHEL host with a network address. This chapter teaches you how to add some command networking services and how to configure NTP, DNS, DHCP, and SMTP, time, name resolution, IP address assignment, and e-mails.
Chapter 4, Implementing iSCSI SANs, discovers RHEL 7. It offers a new kernel-based module to implement network-based storage. This chapter teaches you how to deploy iSCSI targets and connect from an RHEL client.
Chapter 5, Implementing btrfs, takes a look at Better FS. Having volume management built-in the filesystem allows easy storage management and is a common basis for sharing your filesystem on a network.
Chapter 6, File Sharing with NFS, explains NFS, a de facto Unix file sharing service, which still maintains its importance in the Enterprise Linux market. This chapter covers how to use NFSv4 and compares it with V3 so that you can appreciate its easier firewall management feature among many other new features.
Chapter 7, Implementing Windows Shares with Samba 4, covers instances where RHEL can provide services on a network and the client-side workstation will have Windows OS installed at their end. This requires RHEL to support these Windows clients. File and print services can be supplied through the Samba 4 service on RHEL 7.
Chapter 8, Integrating RHEL 7 into Microsoft Active Directory Domains, explores the fact that many enterprise organizations have already set up Identity Services and are run with Microsoft's Active Directory. It makes sense that these existing domain accounts should be used to access resources on the RHEL 7 server. The RHEL server can join the domain server and become a member server that allows you to share single sign-on to shared resources hosted on the Linux system.
Chapter 9, Deploying the Apache HTTPD Server, deploys a web server that can be important for your network. This may be to provision web access to an intranet or external access to the Internet. Many administrators use the Apache web server to provide access to local software repositories and install sources, so the importance of this service cannot be overlooked.
Chapter 10, Securing the System with SELinux, provides insights on the fact that with more and more systems connecting to the Internet, the vulnerability of your network facing services is increasing exponentially. SELinux has been included on RHEL since release 4, but very often, we read blogs that suggest that SELinux should be disabled. This chapter teaches you how to deploy systems with SELinux effectively.
Chapter 11, Network Security with firewalld, provides insights on how to effectively use firewalls on your RHEL 7 system with the latest command-line tool, the firewalld service, and the firewall-cmd command. Throughout the book, we have presented practical uses of the latest firewall and how to open the required ports and services. The book concludes with details of this service and how to effectively secure your server with firewalld.
The book uses Red Hat Enterprise Linux 7.1. Evaluations can be downloaded directly from Red Hat at https://access.redhat.com/downloads.
Should you not want to use RHEL, you may use Fedora 21 or CentOS 7 from:
Fedora can be downloaded from https://getfedora.org/en/workstation/download/
CentOS 7 can be downloaded from http://www.centos.org/download/
This book is designed for Linux administrators or those wanting to learn Linux administration from scratch.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: "The /etc/issue content will be displayed before the logon prompt."
A block of code is set as follows:
zone "tup.local." IN {
type master;
file "named.tup";
};Any command-line input or output is written as follows:
$ sudo vi /etc/named.conf
Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or may have disliked. Reader feedback is important for us to develop titles that you really get the most out of.
To send us general feedback, simply send an e-mail to <[email protected]>, and mention the book title through the subject of your message.
If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide on www.packtpub.com/authors.
Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.
Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you find a mistake in one of our books—maybe a mistake in the text or the code—we would be grateful if you would report this to us. By doing so, you can save other readers from frustration and help us improve subsequent versions of this book. If you find any errata, please report them by visiting http://www.packtpub.com/support, selecting your book, clicking on the errata submission form link, and entering the details of your errata. Once your errata are verified, your submission will be accepted and the errata will be uploaded to our website, or added to any list of existing errata, under the Errata section of that title.
Piracy of copyright material on the Internet is an ongoing problem across all media. At Packt, we take the protection of our copyright and licenses very seriously. If you come across any illegal copies of our works, in any form, on the Internet, please provide us with the location address or website name immediately so that we can pursue a remedy.
Please contact us at <[email protected]> with a link to the suspected pirated material.
We appreciate your help in protecting our authors, and our ability to bring you valuable content.
You can contact us at <[email protected]> if you are having a problem with any aspect of the book, and we will do our best to address it.