You can add the second IP address from the Windows GUI.
- Open the Control Panel –> Network and Internet –> Network and Sharing Center -> Change adapter settings;
- Open the properties of your network interface;
- Select TCP/IP v4 in the list of protocols and click Properties;
4. If you have not Already you will need to set the default IP Address of your Box rather than it forcing DHCP, to do this, let's gather some Information, Open a Command Prompt Window (CMD), and type in ipconfig.
This provides us with our Core IP, the Subnet Mask, and the Default Gateway, Simply copy these 3 fields and place them in their respective slots in the Internet protocol Version 4 (TCP/IPv4) Properties Window.
Below this you will see fields "Use the following DNS server addresses", Feel free to make use of your own personal DNS, Google DNS, or Cloudflare DNS (If you do not place anything here you will lose access to your Box and a technician will have to fix it), For instance I have chosen the Google Public DNS.
5. Once you have set your Initial Core IP/DNS, Click the "Advanced" button, this will open Advanced TCP/IP Settings where you can assign additional IP's that are assigned to your VPS/Dedicated Server.
Note I have already added one additional IP already, However to add an IP it's as simple as clicking the "Add" button, putting in your Additional IP value, It's Subnet Mask (Note that your subnet mask may be different depending on your subnet assignment), and then hitting "Add".
Once you are done Simply click OK, on the Advanced TCP/IP Settings Window, the Internet Protocol Version 4 Window, and the Ethernet Properties Window, Once you have closed the Ethernet Properties Window, YOU MAY LOSE ACCESS to your VPS/Dedicated Server Temporarily whilst it reconfigures your networking for the adjustments you have just made, give it time and it should come back to you automatically, Once you're back head back over to your Command Prompt Window (CMD) and type the following command
the response back should be
Windows IP Configuration
Successfully flushed the DNS Resolver Cache.
Once done type the following
This should hit back with your current Windows IP configuration, and include the additional IP Assignments you have just made
At this point you should be able to ping the IP correctly, and also use it to connect via RDP to your current Box, and that's it!, there are alternative methods of doing this via Netsh and PowerShell, However this guide is intended for Windows GUI for Simplification.