Ultimate Guide to Ubuntu Server Hosts File for Devs

Dear Dev,

If you are looking to manage your network and control access to specific domains, you have come to the right place. Welcome to the ultimate guide to Ubuntu Server Hosts File. In this article, we will explore everything you need to know about Ubuntu Server Hosts File from the basics to some advanced topics. So, let’s get started!

What is Ubuntu Server Hosts File?

The Ubuntu Server Hosts File is a text file that maps domain names to IP addresses. It is used to control access to specific domains on your network. When you type a URL into your browser, your computer checks the Hosts File to determine the IP address associated with that domain name. If the IP address is located in the Hosts File, it will use that IP address. Otherwise, it will check with a DNS (Domain Name System) server to resolve the IP address.

The Hosts File is located in the /etc directory and can be edited using any text editor such as nano or vim. It is important to note that you must have root privileges to modify the Hosts File.

Why Use Ubuntu Server Hosts File?

There are several reasons why you might want to use Ubuntu Server Hosts File:

How to Modify the Ubuntu Server Hosts File

Modifying the Ubuntu Server Hosts File is a simple process:

Step 1: Open the Hosts File

Open the terminal and type:

sudo nano /etc/hosts

This will open the Hosts File in the nano text editor with root privileges.

Step 2: Modify the File

Add the domain name and IP address to the Hosts File using the following format:

IP_address domain_name

For example, if you want to map the domain name example.com to the IP address 192.168.0.1, you would enter:

192.168.0.1 example.com

You can also add comments to the file by starting a line with the “#” symbol.

Step 3: Save and Exit the File

Once you have made your changes, save and exit the file by pressing “CTRL” + “X”, followed by “Y” and “ENTER”.

Advanced Topics

Subdomains

You can also map subdomains to specific IP addresses. For example, if you want to map the subdomain www.example.com to the IP address 192.168.0.2, you would enter:

192.168.0.2 www.example.com

Wildcard Domains

You can use wildcard domains to map all subdomains of a domain to a specific IP address. For example, if you want to map all subdomains of the domain example.com to the IP address 192.168.0.3, you would enter:

192.168.0.3 *.example.com

FAQ

Q: What happens if I map a domain to an invalid IP address?

If you map a domain to an invalid IP address, your computer will not be able to access the domain. Make sure that you verify the IP address before adding it to the Hosts File.

Q: Can I use the Hosts File to block access to certain IP addresses?

No, the Hosts File is used to map domain names to IP addresses. It cannot be used to block access to IP addresses.

Q: How can I test if my Hosts File modifications are working?

You can test your Hosts File modifications by trying to access the domain name in your browser. If the domain is mapped correctly, you should be directed to the IP address specified in the Hosts File.

Q: Can I use the Hosts File to redirect domains to different ports?

No, the Hosts File is only used to map domain names to IP addresses. To redirect domains to different ports, you will need to use other methods such as port forwarding or a reverse proxy server.

Q: How can I reset the Hosts File to its default settings?

To reset the Hosts File to its default settings, delete all the lines in the file except for the first two lines:

127.0.0.1 localhost

::1 localhost ip6-localhost ip6-loopback

Conclusion

Now that you have learned everything you need to know about Ubuntu Server Hosts File, you can start managing your network and controlling access to specific domains. Remember to always verify the IP address before adding it to the Hosts File and to use subdomains and wildcard domains for more advanced configurations.

Thank you for reading, Dev!