Add a sub network interface or additional IP address in Windows Server

You may at some point require a separate local IP address on your network interface, for example, if you have 2 servers in a private VLAN and want to restrict communications on a specific IP, possibly for locking down a database or web application.A separate Network Interface is not required for this, Windows does support additional IPs on a single network card, this acts as a subinterface.The process is very straightforward, the following assumes 2 servers running Windows Server 2019 in a private VLAN.

1. Right-click on the start menu and select ‘Network Connections’ then in the window that opens click ‘Change adaptor options’

2. Locate the Ethernet connection, right-click on it and select ‘properties’

3. In the centre scroll down to find and select ‘Internet Protocol Version 4 (TCP/IPv4) then click the ‘properties’ button below.

4. Your current public IP configuration will then come up, click the ‘Advanced’ Button on the bottom right.

5. In the window that should have just opened named ‘Advanced TCP/IP Settings’ under ‘IP addresses’ click the ‘Add…’ Button

6. Specify a new IP additional address e.g. with subnet and click ‘Add’

7. You will now see the private address under ‘IP addresses, click the ‘OK’ button.

8. Repeat the process above using a different IP in the same subnet for the second server e.g. with subnet

If you just want to add a second public IP address on a single server, for example, if you ordered an extra IP address for your server then you can follow the same process to add the additional IP address with the address details provided when your order is fulfiled.