The Internet Information Services (IIS) Web server allows you to access your website via an IP address and is flexible, secure, and manageable.
You need to bind your website to a non-standard port along with your VPS's public IP address in order to access it through an IP address.
When you bind your website to a non-standard port, you'll be able to check its functionality before making any changes to your DNS (nameservers).
Follow the steps below to configure IIS to access a website through an IP address.
Add a Binding in IIS
1. Login into your Windows server via Remote Desktop. Learn more about how to connect to a Windows Server via Remote Desktop.
2. Go to Start → Administrative Tools → Internet Information Services (IIS) Manager. 
3. In the Connections pane of IIS, expand the Sites and select the website which you want to access via IP address.
4. Click on the Bindings link, and you will see the current bindings of that website.
5. Click on Add button to add a new binding. 
6. In the Add Site Binding window, select 'http' as the website type. Select an IP address from the drop-down list you want to bind. You won't bind the new website on port 80 without Host Header Value (Hostname), as other websites (along with their Host Header Values) are also bound on port 80.
So, specify a port number (other than the default port 80) that you wish to bind to this new website. Keep Hostname as blank, click OK, and then Close. Once the binding is added in IIS Manager, the next step is allowing a port in Windows Firewall.
Open a Port in Windows Firewall
1. Go to Start → Administrative Tools → Windows Firewall with Advanced Security. 
2. At the Windows Firewall window, click on Inbound Rules. 
3. Under the Actions pane, click on New Rule, and New Inbound Rule Wizard will be opened. On this window, select the Port radio button and click on Next.
4. On the next screen, select TCP and Specific local ports radio button. Specify a port number (upon which you set the binding in IIS) in the Specific local ports field and click Next.
5. On the next screen, select Allow the connection and click Next. 
6. Select the profile where you want to apply this rule and click Next.
7. Specify the Name and Description for the newly created rule & click Finish.
Once you allow the port number in Windows Firewall, you will be able to access your website via an IP address like http://VPS-IP-Address:81.
→ Looking to change the Application pool of your website? Please refer to Change Application Pool for more details.
→ Looking to know more details on the Application pool? Please refer to IIS Application Pool for more details.
→ Looking to set the redirection of your website in IIS? Please refer to Set IIS Redirection for more details.
