The hosts file in Windows, Mac, or Linux maps hostnames to IP addresses. For example, an intranet, like a corporate office that has servers for users to access, or it could be domain names for servers on the internet.
Editing your hosts file can be useful if you are running tests on your network. By mapping an IP address to a server name (or domain name), you can skip the process where a web browser uses a Domain Name Server(DNS) lookup to translate the domain name to the IP address.
In this tutorial, learn how to edit hosts file on Linux, Windows, or Mac.
Most Linux distributions have an applications > utilities > terminal feature, or an option to right-click the desktop and click Open Terminal.
To open the Linux hosts file, type the command:
sudo vim /etc/hosts
Instead of Vim, you can use any other text editor, like nano.
The system should prompt for your password – enter it, and the Hosts file should open.
The hosts file in Linux is formatted so that the IP address is first, and the server name is second.
Add any entries you wish to the end of the file. If you make a mistake or need to tell your operating system to ignore a line, add the ‘#’ sign at the beginning of that line.
Make sure you save the file by using shift+z+z key combination before you exit.
You’ll need administrator privileges for this operation.
Click the Windows button and type “notepad.” Let the search feature find the Notepad application.
Right-click the Notepad app, then click Run as administrator.
Windows User Account Control should pop up asking, “Do you want to allow this app to make changes to your device?” Click Yes.
In Notepad, click File> Open
Navigate to c:\windows\system32\drivers\etc
In the lower-right corner, just above the Open button, click the drop-down menu to change the file type to All Files.
Select “hosts” and click Open.
The Windows hosts file is that it gives you a brief explanation of how to write a new line. Here’s a brief breakdown:
The first set of four (4) digits is the IP address you’re mapping. This could be the internal IP address of a server on the network, or it could be the IP address of a website.
The second label is the name you want to be able to type in a browser to access the server at the IP address you just specified.
Once you’re finished making your changes, save the file (File > Save) and exit.
If you make an edit to the hosts file and something stops working, you can tell Windows to ignore any line by putting a # sign at the beginning of that line.
It would look like:
# 0.0.0.0 server.domain.com
Open the Finder, and go to Applications > Utilities > Terminal
Type the following in the terminal window:
sudo nano /private/etc/hosts
The system should prompt you to enter your password – this is the same password you use to log in to the system. Type it in, and hit Enter.
The IP address is first, and the server name comes second. Comments are indicated with a ‘#’ sign. Consider the example below:
Enter the IP address you want to refer to first, hit space, and then the server name (or domain name) that you want to associate with it.
If you make a mistake, you can tell Mac OS to ignore a line by typing a # at the beginning of that line.
Save your changes by pressing Command + O, then exit by pressing Command + X.