In the multi-EIP to ENI mode, the private and public IP addresses of an elastic network interface (ENI) are available at the same time. You can view the Elastic IP address information in the network interface controller (NIC) of the operating system.

Prerequisites

Before you set this mode, make sure that you have met the following requirements:
  • Currently, this mode is in public preview. To use this mode, submit a ticket.
  • The network type of the secondary ENI is VPC.
  • The secondary ENI and the Elastic IP address are in the same region.
  • The secondary ENI is not associated with any ECS instance.

    If the secondary ENI has been associated with an ECS instance, disassociate it from the ECS instance first. After the multi-EIP to ENI mode is configured, you can associate the secondary ENI to the ECS instance again. For more information, see Detach an ENI from an instance.

  • In the multi-EIP to ENI mode, an ENI can be associated with up to 10 Elastic IP addresses. To request a quota increase, submit a ticket.

Background information

An Elastic IP address is actually a NAT gateway IP address. In the NAT mode, the public IP address is assigned to the gateway device rather than the NIC of the ECS instance. In the operating system of the ECS instance, the private IP address of the NIC is visible, but the public IP address is not visible. In this case, administrators need to manually maintain the mapping between the NIC or server and the public IP address. When an Elastic IP address is deployed as a NAT application-level gateway (ALG), protocols such as H.323, SIP, DNS, and RTSP are not supported.

In the Multi-EIP to ENI Mode, the Elastic IP address is visible on the NIC, which addresses the preceding problem. In the multi-EIP to ENI mode:
  • The secondary ENI still supports private networks.
  • The Elastic IP address is visible on the NIC. After you configure a static IP address in the operating system, you can run the ifconfig or ipconfig command to query the public IP address on the ENI.
  • Elastic IP addresses support all IP protocols, such as FTP, H.323, SIP, DNS, RTSP, and TFTP.

Procedure

  1. Log on to the VPC console.
  2. In the left-side navigation pane, click Elastic IP Addresses.
  3. In the upper-left corner, select the region where the Elastic IP address is deployed.
    Note Currently, the multi-EIP to ENI mode is supported in the following regions: China (Shenzhen), China (Shanghai), China (Beijing), China (Zhangjiakou), Singapore, Germany (Frankfurt), India (Mumbai), and UK (London).
  4. On the Elastic IP Addresses page, find the target Elastic IP address, and then click Bind in the Actions column.
  5. In the Bind Elastic IP Address dialog box, set the following parameters and click OK.
    Parameter Description
    Instance Type The type of the instance. Select Secondary ENI.
    Resource Group The resource group to which the Elastic IP address belongs.
    Mode Select Multi-EIP to ENI Mode.
    Secondary ENI The secondary ENI with which you want to associate the Elastic IP address.
    Associate an Elastic IP address with an ENI
  6. To associate more Elastic IP addresses to the secondary ENI, repeat the preceding steps.
  7. After the Elastic IP address is associated with the ENI, click the link of the ENI.
    View the associated ENI
  8. In the ENI list, click Bind Instance to associate the ENI with an ECS instance.
    Note
    • In the multi-EIP to ENI mode, you can associate an Elastic IP address with the secondary ENI, and then associate the secondary ENI with an ECS instance. Supported ECS instance families include: ecs.c5-618, ecs.d1ne, ecs.db11-se1ne, ecs.ebma1, ecs.ebmc4, ecs.ebmg4, ecs.ebmg5, ecs.ebmg5ne, ecs.ebmgn5i, ecs.ebmgn5t, ecs.ebmhfg4, ecs.ebmhfg5, ecs.ebmi2, ecs.ebmi3, ecs.ebmr4, ecs.ebmr5, ecs.elmd1ne, ecs.elmdb, ecs.f1, ecs.f2, ecs.g5-618, ecs.gn3, ecs.gn5d, ecs.gn5i, ecs.gn5t, ecs.gn6p, ecs.gn6v, ecs.i2, ecs.r1, ecs.re4, ecs.re4e, ecs.sccg5, ecs.sccgn6, ecs.scch5, ecs.x1.i2, ecs.x1.i5, ecs.x1.i6, ecs.x1.i8, ecs.g5, ecs.c5, ecs.r5, ecs.t5, ecs.sn2ne, ecs.se1ne, and ecs.sn1ne. For more information, see Instance families.
    • After you set the multi-EIP to ENI mode, the ECS instance associated with the secondary ENI must have DHCP enabled. Otherwise, this mode cannot be enabled.
  9. You can call the DescribeEipGatewayInfo operation to query the gateway and subnet mask information about an Elastic IP address. For more information, see DescribeEipGatewayInfo.
  10. Log on to the ECS instance and configure multiple Elastic IP addresses for the ECS instance. For more information, see Assign a secondary private IP address for a Windows instance and Assign a secondary private IP address to a Linux instance.
    Notice As described in the preceding topics, change the secondary private IP address to the Elastic IP address, and the gateway and subnet mask of the secondary private IP address to those of the Elastic IP address.
    After you set the Elastic IP address, you can run the ifconfig or ipconfig command to query the Elastic IP address.
  11. Optional. After you set the multi-EIP to ENI mode, you can test the network connectivity. For more information, see Test the network connectivity.