Convert a static public IP address to an Elastic IP Address (EIP) to freely reassign it across cloud resources, such as ECS instances, SLB instances, and NAT gateways.
Static public IP address vs. EIP
Both provide Internet access but differ in assignment and flexibility.
Feature | Static public IP address | EIP |
Assignment | Assigned when you create a VPC-type ECS instance, or later by modifying the bandwidth configuration. See Static public IP addresses. | Purchased and managed independently. See Elastic IP addresses. |
Flexibility | Bound to a single ECS instance. Cannot be reassigned. | Can be reassigned to another resource at any time. |
Billing impact
The public bandwidth billing method stays the same, but the EIP is billed separately with different billing items. Configuration and association fees may apply. See EIP billing.
Limitations
This conversion is irreversible. To obtain a new static public IP address, disassociate the EIP and modify the instance's public bandwidth. See Modify the bandwidth configurations of subscription instances or Modify the bandwidth configurations of pay-as-you-go instances. You can also call ModifyInstanceNetworkSpec to assign a new static public IP address.
The IP address remains the same after conversion.
The static public IP address cannot be on a BGP (Multi-ISP) Pro line in the China (Hong Kong) region.
Prerequisites
Make sure that:
The ECS instance is in a VPC and has a static public IP address
The ECS instance is in the Running or Stopped state
For subscription instances, public bandwidth uses pay-by-traffic. If billed by pay-by-bandwidth, switch to pay-by-traffic first. See Change from pay-by-bandwidth to pay-by-traffic
For subscription instances, the instance is not within 24 hours of expiration
For pay-as-you-go instances, your account has no overdue payment
Any recent instance type change has taken effect
Convert a static public IP address to an EIP
You can also call ConvertNatPublicIpToEip to perform this conversion. Use SDK version 4.3.0 or later. See Install and use ECS SDKs.
Go to the Instances page of the ECS console.
In the top navigation bar, select the region and resource group.
Find the target instance (network type: VPC). Click All Actions > Network and Security Group > Convert to EIP.
In the dialog box, click Confirm.
Refresh the instance details page.
Verify the result
After conversion, the Public IP Address field is empty and the converted IP address appears in the EIP field.
Click the IP address to open the Elastic IP Addresses console to manage the EIP.
Next steps
After the conversion, you can:
Reassign the EIP -- Disassociate the EIP and associate it with another ECS or SLB instance. See Associate or disassociate an EIP.
Reduce bandwidth costs -- Use Internet Shared Bandwidth to optimize costs across multiple EIPs. See Reduce the costs of data transfer over the Internet.
Release the EIP -- Release the EIP to stop incurring charges. See Release a pay-as-you-go EIP.