Elastic IP (EIP) is a public IP address resource that you can purchase and possess independently. EIP can be dynamically bound to a VPC ECS instance without restarting the ECS instance.
An EIP address is a NAT IP. It is located in the public network gateway of Alibaba Cloud, and mapped to the private network interface card (NIC) of the bound ECS instance in the way of NAT. Therefore, the ECS instance with a bounded EIP can communicate with the Internet without disclosing its EIP in the NIC.
Note: Currently, only ECS instances support the binding of an EIP address.
- Independently purchased and possessed
- You can purchase an EIP independently instead of bundling with other computing resources or storage resources.
- You can possess an EIP as an independent resource in your account.
- Flexible binding
- You can bind an EIP to an ECS instance in any VPC to make the instance accessible to the Internet, and release it whenever Internet communication is not needed.
- Configurable network capabilities
- You can adjust the bandwidth of an EIP as needed. The bandwidth changes take effect immediately.
The following table lists the differences between EIP addresses and ECS public IP addresses.
|Comparison items||EIP||ECS public IP|
|Dynamically binding and unbinding to and from ECS instances||Yes||No|
|Viewed on the NIC of ECS instances||No||Yes|