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Before DNS servers were in use, Windows computers used a “Hosts” file to map an IP address to an easy to remember domain name (like itflee.com). This host file still exists, so let’s go take a look at it. Open Windows Explorer and navigate to “C:\Windows\System32\Drivers\etc\”. We are looking for a file called “hosts”.

In order to edit this file, you will need to open a text editor with administrative rights. Click the Windows Button and search for Notepad. Right-click notepad and select Run as administrator.

Next, drag the hosts file into the text editor. You will now see the contents of the hosts file and are free to make changes.
This file is commonly manipulated by hackers to do what is called DNS poisoning. Meaning, they enter a different IP address for a commonly website like facebook.com, but instead of putting FaceBooks IP address they put in the IP address of a malicious website that looks like FaceBook but instead steals user names and passwords or other personal information.

To help you understand how this file works, let’s create an entry called mytestentry and map it to a loopback IP address. A loopback IP address (127.0.0.1) references the computer you are currently logged in to. First, let’s open Command Prompt and attempt to ping mytestentry and see what happens.

Of course, there is no hostname called mytestentry because our DNS server does not have a record of it, and it is not in the hosts file. So now we are going to create an entry for it.
Go back to notepad and at the bottom of the hosts file type 127.0.0.1 mytestentry. The 127 IP address is the loopback IP we talked about earlier, and mytestentry is the hostname we want to reference this IP address.
Save the file and switch back to Command Prompt. Press the up arrow to select the command we entered before, and press Enter.

Now we can see that we were able to ping mytestentry. We can see that it attempted to ping at 127.0.0.1 and got a reply. Of course, we could have used any hostname we wanted to, but for this example, I wanted to use something that likely was not in use.
Now the last thing we need to do is remove the entry from our hosts file as we no longer need it. Go back to Notepad and remove the line we had just added and save the file once again. Notice that if you go back to Command Prompt and attempt to ping mytestentry it will again say it could not find the host.
An import fact for you to keep in mind is that the hosts file only affects the local computer and has no effect on any other computers on the network. So you if tried to ping mytestentry from another computer on your network it would not be able to find the host because each computer only looks at its own hosts file and not any other computer’s hosts file.
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CURRICULUM
Course Introduction • 10min
0 / 2 lessons complete
Instructor and Course Introduction
Video | 7 min
What's New in Windows Server 2016 DNS
Free lesson
Video | 3 min
DNS Basics • 56min
0 / 8 lessons complete
What is DNS
Video | 3 min
Installing the DNS Windows Server Role
Video | 6 min
Building DNS Server Quiz
Quiz | 10 Questions
The Hosts File
Video | 4 min
DNS Console Overview
Video | 7 min
Recursive and Iterative Queries
Video | 8 min
DNS Basics LAB
Video | 10 min
DNS Basics Quiz
Quiz | 8 Questions
DNS Resource Records • 45min
0 / 5 lessons complete
DNS Resource Record Types
Video | 3 min
Creating the mytestzone Forward Lookup Zone
Text | 2 min
Creating DNS Resource Records
Video | 4 min
Creating DNS Resource Records Lab
Lab | 30 min
DNS Resource Records Quiz
Quiz | 7 Questions
DNS Zones • 4hr 11min
0 / 12 lessons complete
DNS Zones
Video | 4 min
Creating a Forward and Reverse Lookup Zone
Video | 5 min
Creating a Secondary Zones
Video | 9 min
Stub Zone Creation
Video | 11 min
Active Directory Zone Replication
Video | 12 min
Implementing DNS Forwarding
Video | 8 min
Implementing Conditional DNS Forwarding
Video | 7 min
Forward and Reverse Zone Creation Lab
Lab | 60 min
Creating a Secondary Zone Lab
Lab | 30 min
Conditional Forwarding Lab
Lab | 60 min
Creating a Stub Zone Lab
Lab | 30 min
DNS Zones Quiz
Quiz | 15 Questions
DNS Delegation • 50min
0 / 4 lessons complete
Domain Name System and DNS Delegation
Video | 7 min
Windows 2016 Server and DNS Zone Delegation
Video | 8 min
DNS Delegation Lab
Lab | 30 min
QUIZ - Domain Name System and DNS Delegation
Quiz | 5 Questions
DNS Security Techniques • 36min
0 / 5 lessons complete
DNS Security Techniques Overview
Video | 9 min
Configuring DNS Cache Locking
Video | 5 min
Configuring DNS Socket Pools
Video | 6 min
Configuring Response Rate Limiting
Video | 8 min
DNS Security Techniques Quiz
Quiz | 8 Questions
Advanced DNS Topics • 22min
0 / 5 lessons complete
Overview of Advanced Topics
Video | 1 min
Enabling Round Robin and Netmask Ordering
Video | 5 min
Configuring Recursion
Video | 4 min
IPV4 and IPV6 Root HInts
Video | 6 min
Advanced DNS Topics Quiz
Quiz | 6 Questions
DNS Security (DNSSEC) • 1hr 16min
0 / 6 lessons complete
Windows DNS Security Overview
Video | 7 min
Symmetric vs Asymmetric Encryption
Video | 5 min
Installing DNSSEC on Windows 2016 Server
Video | 12 min
DNSSEC Client Install
Video | 7 min
DNSSEC (DNS Security Lab)
Lab | 30 min
DNSSEC Quiz
Quiz | 15 Questions
DNS Policies • 55min
0 / 6 lessons complete
DNS Policies Background Information
Video | 8 min
Configuring DNS Filtering
Video | 7 min
Configuring Split Brain DNS in an Active Directory Environment
Video | 12 min
Configuring DNS Selective Recursion Policy
Video | 7 min
Configuring a Traffic Management Policy
Video | 11 min
DNS Policies Quiz
Quiz | 10 Questions
PowerShell for DNS • 1hr 27min
0 / 6 lessons complete
PowerShell for DNS Part 1
Video | 2 min
PowerShell for DNS Part 2
Video | 5 min
PowerShell for DNS Part 3
Video | 10 min
PowerShell for DNS Part 4
Video | 5 min
PowerShell for DNS LAB
Lab | 60 min
Powershell for DNS Quiz
Quiz | 5 Questions
Troubleshooting DNS Issues - Troubleshooting Tools • 1hr 39min
0 / 8 lessons complete
Troubleshooting Tools Every IT Pro Must Know
Video | 9 min
The Events Viewer Overview
Video | 6 min
Subscriptions
Video | 9 min
Monitoring and Debug Logging
Video | 9 min
Trouble-Shooting DNS Client Issues
Video | 4 min
Troubleshooting Subscriptions Lab
Lab | 30 min
DNS Troubleshooting Lab
Lab | 30 min
DNS Troubleshooting Quiz
Quiz | 2 Questions