Tag Archives: Networking

DNS

How To Configure BIND as a Private Network DNS Server on Ubuntu 14.04

Leave a comment

Introduction

An important part of managing server configuration and infrastructure includes maintaining an easy way to look up network interfaces and IP addresses by name, by setting up a proper Domain Name System (DNS). Using fully qualified domain names (FQDNs), instead of IP addresses, to specify network addresses eases the configuration of services and applications, and increases the maintainability of configuration files. Setting up your own DNS for your private network is a great way to improve the management of your servers.

In this tutorial, we will go over how to set up an internal DNS server, using the BIND name server software (BIND9) on Ubuntu 14.04, that can be used by your Virtual Private Servers (VPS) to resolve private host names and private IP addresses. This provides a central way to manage your internal hostnames and private IP addresses, which is indispensable when your environment expands to more than a few hosts.

The CentOS version of this tutorial can be found here.

Prerequisites

To complete this tutorial, you will need the following:

  • Some servers that are running in the same datacenter and have private networking enabled
  • A new VPS to serve as the Primary DNS server, ns1
  • Optional: A new VPS to serve as a Secondary DNS server, ns2
  • Root access to all of the above (steps 1-4 here)

If you are unfamiliar with DNS concepts, it is recommended that you read at least the first three parts of our Introduction to Managing DNS. Continue reading How To Configure BIND as a Private Network DNS Server on Ubuntu 14.04 →

DNS

A Comparison of DNS Server Types: How To Choose the Right DNS Configuration

Leave a comment

Introduction

DNS, or the Domain Name System, is an integral part of how systems connect with each other to communicate on the internet. Without DNS, computers, and the people who use them, would be required to connect using only numerical addresses known as IP addresses.

Besides the obvious problem of having to remember a large number of complex numbers for simple tasks, communicating through IP addresses also causes some additional problems. Moving your website to a different hosting provider, or moving your servers to different locations would require you to inform every client of the new location.

DNS servers, the computers that together form the system that allow us to use names instead of addresses, can server many different functions, each of which can contribute to your ability to accessing servers by name.

In a previous guide we discussed some of the basic terminology and concepts of the domain name system. We will assume some familiarity with the concepts covered in that article. In this guide, we will talk about some of the different types of DNS server setups and what the advantages, use cases, and properties are of each. Continue reading A Comparison of DNS Server Types: How To Choose the Right DNS Configuration →

Linux

How To Mitigate DDoS Attacks Against Your Website with CloudFlare

Leave a comment

How To Mitigate DDoS Attacks Against Your Website with CloudFlare

Introduction

CloudFlare is a company that provides content delivery network (CDN) and distributed DNS services by acting as a reverse proxy for websites. CloudFlare’s free and paid services can be used to improve the security, speed, and availability of a website in a variety of ways. In this tutorial, we will show you how to use CloudFlare’s free tier service to protect your web servers against ongoing HTTP-based DDoS attacks by enabling “I’m Under Attack Mode”. This security mode can mitigate DDoS attacks by presenting an interstitial page to verify the legitimacy of a connection before passing it to your web server.

Prerequisites

This tutorial assumes that you have the following:

  • A web server
  • A registered domain that points to your web server
  • Access to the control panel of the domain registrar that issued the domain

You must also sign up for a CloudFlare account before continuing. Note that this tutorial will require the use of CloudFlare’s nameservers.

Configure Your Domain to Use CloudFlare

Before using any of CloudFlare’s features, you must configure your domain to use CloudFlare’s DNS.

If you haven’t already done so, log in to CloudFlare. Continue reading How To Mitigate DDoS Attacks Against Your Website with CloudFlare →