If you had to administer some Windows webservers based on IIS and you're coming from the Linux realm, it would be really confusing on how you can use a single IP address to have binded multiple domain certificates.
For those who have done it on linux, they know Apache and other webservers in recent versions support the configuration Directive of a Wildcard instead of IP through the SNI extension capble to capture in the header of the incoming SSL connection the exact domain and match it correctly against the domain with the respective certificate. Below is what I mean, lets say you have a website called yourdomain.com and you want this domain to be pointing to another location for example to yourdomain1.com
For example in Apache Webserver this is easily done by defining 2 separate virtualhost configuration files similar to below:
/etc/apache2/sites-available/yourdomain.com
<Virtualhost *>
…
Servername yourdomain.com
ServerAlias www.yourdomain.com
….SSLCertificateFile /etc/letsencrypt/live/yourdomain1.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/yourdomain1.com/privkey.pem
</VirtualHost>
/etc/apache2/sites-available/yourdomain1.com
<Virtualhost *>
…
Servername yourdomain1.com
ServerAlias yourdomain1.com
…
SSLCertificateFile /etc/letsencrypt/live/yourdomain1.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/yourdomain1.com/privkey.pem
</VirtualHost>
Unfortunately for those who still run legacy Windows servers with IIS version 7 / 7.5 your only option is to use separate IP addresses (or ports, but not really acceptable for public facing sites) and to bind each site with it's SSL certificate to that IP address.
IIS ver. 8+ supports the Server Name Indication extension of TLS which will allow you to bind multiple SSL sites to the same IP address/port based on the host name. It will be transparent and the binding will work the same as with non-HTTPS sites.
In Microsoft IIS Webserver to configure, it is not possible to simply edit some configurations but you have to do it the clicking way as usually happen in Windows. thus you will need to have generated the Domain Certificate requests and so on and then you can simply do as pointed in below screenshots.
