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    Elastic IP Address:Features and Limitations FAQ

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    Elastic IP Address:Features and Limitations FAQ

    Last Updated:Sep 20, 2026

    This topic answers common questions about the features and limitations of Elastic IP Addresses (EIPs).

    EIP vs. static public IP address

    VPC resources use public IPv4 addresses for internet access. These addresses are categorized as static public IPs and EIPs.

    A static public IP is assigned only at resource creation (such as ECS or Classic Load Balancer (CLB) instances) and cannot be disassociated or reassigned—it is released when the resource is deleted. An EIP is an independent resource you can dynamically associate or disassociate, providing greater management flexibility. We recommend EIPs.

    Checking the public IP type

    Log on to the ECS console, select the target ECS instance, and click the instance ID to open its details page. The public IP address information is displayed on this page.

    The type of IP address is indicated on the page:

    • Public IP Address: Indicates that the ECS instance is associated with a static public IP address.

    • EIP: Indicates that the ECS instance is associated with an EIP.

    EIP quota

    By default, you can hold up to 20 EIPs per account. You can request a quota increase.

    Are API calls for EIPs rate-limited?

    The system throttles API requests if a user makes more than 500 API calls per day.

    Using EIPs for DNS resolution

    Yes, you can resolve a website domain name to an EIP. You can also use a private IP address for private DNS resolution. For more information, see Add a website resolution.

    Editing the EIP description

    You can typically edit an EIP's description on its details page. However, this is not possible if the EIP is managed by a third-party service. For example, you cannot edit the description of an EIP that is automatically allocated when you create an internet-facing Network Load Balancer (NLB) instance.

    Converting BGP (Multi-ISP) to BGP (Multi-ISP) Pro

    No.

    You can select an EIP's line type only during creation and cannot change it afterward.

    Changing the public IP address

    Public IP type

    Actions

    Change an EIP

    1. (Optional) Apply for a new EIP.

    2. Disassociate the current EIP from the ECS instance.

      Important

      • After you disassociate a pay-as-you-go EIP from a cloud resource, you are still charged an EIP configuration fee. To avoid unnecessary fees, release the EIP.

      • If you no longer require a subscription EIP after you disassociate the EIP from a cloud resource, you can unsubscribe from the EIP. For more information, see Rules for unsubscribing from resources.

    3. Associate the new EIP with the ECS instance.

    Change a static public IP address

    • You can directly change the static public IP address of an ECS instance within six hours of its creation.

    • After six hours, you must first convert the static public IP address to an EIP and disassociate it. You can then assign a new static public IP address by setting the public bandwidth of the ECS instance to a value greater than 0 Mbps.

    Does an EIP change?

    No, an EIP does not change.

    An EIP may be released due to instance expiration or overdue account payments. If an EIP is released, you can try to retrieve it by applying for a specific EIP.

    A static public IP address is released if the associated ECS instance is released, its public bandwidth is set to 0 Mbps, or the instance is stopped in Economical Mode. When a new static public IP address is assigned to the instance, Alibaba Cloud cannot guarantee that it will be the same as the previous one.
    If you need to assign a public IP address to different ECS instances or want to retain a public IP address after an instance is released, we recommend using EIP. Compared to static public IP addresses, EIP are more flexible and can be associated with and disassociated from ECS instances. You can also convert a static public IP address to an EIP.

    EIP added to a blacklist

    For security reasons, Alibaba Cloud blocks TCP port 25 by default. If you need to send outbound email, we recommend using Alibaba Mail.

    If you use an EIP instead of Alibaba Mail for sending emails and your IP address is added to the blacklist of an international anti-spam organization, such as Spamhaus, you must contact the organization to submit an appeal. For example, follow the Spamhaus PBL delisting process to remove your EIP from their blacklist.

    How do I resolve throttling errors when changing resource groups for EIPs?

    If a throttling error occurs when you change resource groups for multiple EIPs, the resource group API request rate limit may have been reached. This does not mean that EIP bandwidth or data transfer has exceeded a limit. Check the error code returned by the API to confirm the cause.

    For the MoveResourceGroup operation in VPC API, the published rate limit is 60 requests per 60 seconds. This quota counts API requests, not console clicks or batches. Check the rate limits for the operation you actually call, and use the effective quota shown in Quota Center.

    Process changes in batches, reduce concurrency, and pace requests according to the API quota. Avoid sending many requests at once. If throttling occurs, wait before retrying and progressively increase the retry interval. Before retrying, check the operation results and retry only unsuccessful changes.