How do I assign a custom primary private IP address to my Amazon EC2 instance?

You can associate a custom IP address to your EC2 instance while the instance is being configured prior to launch. However, the IP address must be:

• A valid IPv4 address
• In the CIDR range of the chosen subnet
• Available—that is, it must not be tied to any other resource

Note: It's not possible to assign a new custom primary private IP address to an existing instance.

1. Configure an EC2 instance. For detailed steps, see Launching an Instance Using the Launch Instance Wizard.
2. In the Configure Instance Details section, for Network, select a VPC, or create a new VPC. For Subnet, select the subnet, or create a new subnet where you want to launch your instance.
3. In the Network interfaces section, enter the custom private IPv4 address.
4. Finish configuring and then launch the instance.