An EIP is an independent public IP resource. You can convert the static public IP address of a VPC-based ECS instance to an EIP to gain more flexible association and billing options:
Failover: When an ECS instance fails, you can quickly unbind the EIP and associate it with a standby instance to ensure business continuity.
Architecture upgrades: You can decouple the EIP from the ECS instance and associate it with a Load Balancer (SLB) or NAT Gateway to gracefully scale out your network architecture.
Impacts of conversion
IP stays the same: The public IP address does not change during the conversion process, ensuring existing network connections are unaffected.
Billing changes: The billing method and unit price of your public bandwidth remain unchanged. After conversion, the EIP produces its own separate bill, which includes an EIP configuration fee and internet bandwidth/data transfer fees.
When the configuration fee is waived.
One-way conversion: You cannot directly convert an EIP back to a static public IP. If you need a static public IP again, you must release the EIP and adjust the ECS instance's public bandwidth settings to allocate a *new* static public IP. (The IP address will change).
Prerequisites
Before converting, ensure your ECS instance meets the following requirements:
Instance state:
The ECS instance must be in the Running or Stopped state.
If a pending instance specification change exists, you must wait for the change to take effect before executing the conversion.
Billing method:
Pay-as-you-go instances: The account must not have overdue payments.
Subscription instances:
The bandwidth billing method must be configured as Pay-By-Traffic. Instances using fixed-bandwidth billing cannot be converted.
The instance must have at least 24 hours remaining before its expiration time.
Regional restrictions: Static public IP addresses using the BGP (Multi-ISP) Pro line in the China (Hong Kong) region do not support conversion to EIP.
Convert the IP address
Console
Go to ECS console - Instances page.
Find the target VPC-based instance. In the Actions column, choose Network and Security Group > Convert to EIP.
Confirm the conversion information and click OK.
API
Call ConvertNatPublicIpToEip to convert the static public IP to an EIP programmatically.
Verify the result
After a successful conversion, verify the details on the ECS instance details page:
The Public IP Address field will no longer display an IP address (it shows -).
The EIP field will display the newly converted EIP address.
You can now click the EIP address to manage it directly within the EIP console.