Before you use elastic IP addresses (EIPs), make sure that you understand the limits of EIPs.

General limits

General limits of EIPs:
  • You can apply for at most 20 EIPs with each Alibaba Cloud account.

    You can go to the Quota Management page to increase the quota. For more information, see Manage quotas.

  • You can associate an EIP with only one cloud resource. The EIP that you want to associate must be in the Available state. After you associate an EIP with a cloud resource, the EIP immediately takes effect.
  • If an EIP is locked for security purposes, you cannot release the EIP, associate the EIP with a cloud resource, or disassociate the EIP from a cloud resource.
  • The following table describes the bandwidth limits of EIPs.
    Pay-by-data-transfer EIP Pay-by-bandwidth EIP
    The bandwidth limit of a pay-by-data-transfer EIP cannot be higher than 200 Mbit/s. This value indicates the upper limit of bandwidth usage. The bandwidth limit is only for reference and is not a guaranteed value. In scenarios where demands exceed resource supplies, the peak bandwidth may be lower than the bandwidth limit value. The bandwidth limits of pay-by-bandwidth EIPs cannot be higher than 500 Mbit/s. The bandwidth limit is a guaranteed value. In scenarios where demands exceed resource supplies, the peak bandwidth is guaranteed.
    For each Alibaba Cloud account, the sum of the peak bandwidth of all pay-by-data-transfer EIPs in a region cannot exceed 5 Gbit/s. If your business requires guaranteed bandwidth or larger bandwidth, you can purchase pay-by-bandwidth EIPs. For each Alibaba Cloud account, the sum of the bandwidth limits of all pay-by-bandwidth EIPs in a region cannot exceed 50 Gbit/s. You can contact the product manager from Alibaba Cloud to increase the quota.
  • The following limits apply to the inbound and outbound bandwidth of EIPs that are purchased after 00:00 (UTC+8) on February 15, 2020:
    • Inbound bandwidth (data is transmitted to EIPs)
      • If the bandwidth limit of the EIP that you purchased is equal to or higher than 10 Mbit/s, the inbound bandwidth allocated to the EIP equals the bandwidth limit of the EIP.
      • If the bandwidth limit of the EIP that you purchased is lower than 10 Mbit/s, the inbound bandwidth allocated to the EIP is 10 Mbit/s.
    • Outbound bandwidth (data is transmitted from EIPs)

      The outbound bandwidth allocated to an EIP equals the bandwidth limit of the EIP.

Limits on associating an EIP with an ECS instance

Before you associate an EIP with an Elastic Compute Service (ECS) instance, take note of the following limits:
  • The ECS instance must be deployed in a virtual private cloud (VPC).
  • The ECS instance and the EIP must be deployed in the same region.
  • The ECS instance must be in the Running or Stopped state.
  • The ECS instance is not assigned a static public IP address. In addition, the ECS instance is not associated with another EIP.
  • Each ECS instance can be associated with only one EIP. If you want to associate multiple EIPs with an ECS instance, you can associate the EIPs with secondary elastic network interfaces (ENIs). Then, associate the secondary ENIs with the ECS instance.
    • You can associate multiple secondary ENIs with an ECS instance. Make sure that an EIP is associated with each secondary ENI. The number of secondary ENIs that can be associated with an ECS instance varies based on the specification of the ECS instance. For more information, see Instance families.
    • If you associate an EIP with a secondary ENI in NAT Mode, you can associate multiple EIPs with the secondary private IP address of the secondary ENI. Then, you can associate the secondary ENI with an ECS instance. For more information, see Associate multiple EIPs with a secondary ENI in NAT mode.

Limits on associating an EIP with a NAT gateway

Before you associate an EIP with a NAT gateway, take note of the following limits:
  • You did not purchase a NAT service plan before January 26, 2018 with the Alibaba Cloud account to which the NAT gateway belongs.
  • The NAT gateway and the EIP must be deployed in the same region.
  • You can associate at most 20 EIPs with a NAT gateway. You can associate at most 10 pay-by-data-transfer EIPs with a NAT gateway.

    You can go to the Quota Management page to increase the quota. For more information, see Manage quotas.

Limits on associating an EIP with an SLB instance

Before you associate an EIP with a Server Load Balancer (SLB) instance, take note of the following limits:
  • The SLB instance must be deployed in a VPC.
  • The SLB instance and the EIP must be deployed in same region.
  • You can associate only one EIP with each SLB instance.

Limits on associating an EIP with a secondary ENI

Before you associate an EIP with a secondary ENI, take note of the following limits:
  • The secondary ENI must be deployed in a VPC.
  • The secondary ENI and the EIP must be deployed in the same region.
  • You can associate an EIP with a secondary ENI in NAT mode or cut-through mode.
    • The number of EIPs that you can associate with a secondary ENI in NAT mode depends on the number of private IP addresses of the secondary ENI.
    • You can associate only one EIP with each secondary ENI in cut-through mode.

Limits on using EIPs of Border Gateway Protocol (BGP)

Starting 00:00 (UTC+8) on December 22, 2020, you cannot purchase EIPs of BGP (Multi-ISP) International in the China (Hong Kong) region. EIPs of BGP (Multi-ISP) International that are purchased before 00:00 (UTC+8) on December 22, 2020 are not affected.