Book Image

Linux for Networking Professionals

By : Rob VandenBrink
1 (1)
Book Image

Linux for Networking Professionals

1 (1)
By: Rob VandenBrink

Overview of this book

As Linux continues to gain prominence, there has been a rise in network services being deployed on Linux for cost and flexibility reasons. If you are a networking professional or an infrastructure engineer involved with networks, extensive knowledge of Linux networking is a must. This book will guide you in building a strong foundation of Linux networking concepts. The book begins by covering various major distributions, how to pick the right distro, and basic Linux network configurations. You'll then move on to Linux network diagnostics, setting up a Linux firewall, and using Linux as a host for network services. You'll discover a wide range of network services, why they're important, and how to configure them in an enterprise environment. Finally, as you work with the example builds in this Linux book, you'll learn to configure various services to defend against common attacks. As you advance to the final chapters, you’ll be well on your way towards building the underpinnings for an all-Linux datacenter. By the end of this book, you'll be able to not only configure common Linux network services confidently, but also use tried-and-tested methodologies for future Linux installations.
Table of Contents (20 chapters)
1
Section 1: Linux Basics
4
Section 2: Linux as a Network Node and Troubleshooting Platform
8
Section 3: Linux Network Services

Chapter 6 – DNS Services on Linux

  1. DNSSEC implements records that allow "signing" to validate DNS response data. It does not encrypt either the request or the response, so it can operate using the standard DNS ports of udp/53 and tcp/53. DoT fully encrypts DNS requests and responses using TLS. Because DoT is an entirely different protocol, it uses port tcp/853.
  2. DoH behaves as an API—the requests and responses are carried within HTTPS traffic with a specific HTTP header. A DoT Uniform Resource Locator (URL) has a default "landing" site of /dns-query, and because of the HTTPS transport, the protocol uses only tcp/443.
  3. An internal DNS server would definitely implement recursion and forwarders, to allow the resolution of internet hosts. Usually, auto-registration is enabled, and requests are normally limited to "known" subnets that are within the organization.

    External DNS servers for an organization's zone will normally not implement...