If a migration has been done and you want to check if the website is working correctly or simply want to see the website on a server where the DNS does not point, you will need to modify the hosts file on your Mac. This way the request will go where the hosts file points and not where the DNS takes it.

Mac OS X has a tool called Terminal, which is the command console for other systems. We run this and type the following line

sudo nano /private/etc/hosts

It will ask for the root user's password, which usually coincides with the access password to the computer.

* NOTE: Keep in mind that while you type the password, it will not be displayed, not even the "*" symbol, and the cursor will move, just type it and press enter. This is managed this way for security reasons.

We are not going to modify anything that is already in this file, we go to the last line and include the following one line below

First the IP of our server, our domain and then our domain with subdomains (www, webmail....)

example

this way, even if the DNS of myweb.com points to a server with an IP different from 123.123.123.123, when accessing the website from the computer with the modified hosts file, it will enter the server 123.123.123.132

another example:

if you include this in the hosts file on your computer and try to enter google.com, it will load the google.com website from the server 1.1.1.1

the subdomain webmail.com will try to load it from the server with IP 2.2.2.2