The hosts file is used to map hostnames (in other words domains) to IP addresses. With the hosts file you can change the IP address that you resolve a given domain name to. This change only affects your own computer without affecting how the domain is resolved worldwide. This is particularly useful when you wish to see how a website will look like when hosted on a different server without making any DNS changes to your domain.

The location of the hosts file, depending on the operating system that you are using, is:

• Windows, your hosts file is most probably: C:\Windows\System32\drivers\etc\hosts)
• Linux – /etc/hosts
• Mac OS X – /private/etc/hosts

To set this up, all you do is use a text editor and use admin privileges as needed to edit the file. From there, we use the following layout:

• <yourIpRedirect>    <yourDomain.com> <www.yourDomain.com>

Examples:

• 0.0.0.0    webfm.com www.webfm.com
• 127.0.0.1    webfm.com www.webfm.com
• 192.168.1.8    webfm.com www.webfm.com
• 172.217.5.4    webfm.com www.webfm.com

It’s worth noting that you can not add an IP port here and some names you give as the domain don’t always redirect if you’re going to a site than sinking it to your localhost address. Also, if you have a local server, simply append the port to the domain when accessing it. So, http//webfm.com; via the browser would look like:

• http://webfm.com:<portNumber>

That’s it, this is a quick rundown of the hosts file and how it can be used.