You can use elastic network interfaces (ENIs) to deploy high-availability clusters and perform cost-effective failover and fine-grained network management. This topic describes how to separately create an ENI.
Prerequisites
A virtual private cloud (VPC) is created in a region, and a vSwitch is created in the VPC. For more information, see Create and manage a VPC and Create and manage a vSwitch.
A security group is created in the created VPC. For more information, see Create a security group.
Background information
You can use one of the following methods to create an ENI. This topic describes how to separately create an ENI.
Create an ENI when you create an instance.
When you create an instance, a primary ENI is automatically bound to the instance and you can bind only a secondary ENI to the instance. If the secondary ENI is not unbound from the instance before you release the instance, the secondary ENI is released together with the instance.
Separately create an ENI.
To better manage and extend network capabilities of instances, such as adding more private IP addresses, building high-available network environments, and creating dedicated network traffic, you can separately create an ENI. Separately created ENIs are secondary ENIs that can be bound to instances.
Procedure
Log on to the ECS console.
In the left-side navigation pane, choose .
In the upper-left corner of the top navigation bar, select a region.
Click Create ENI.
In the Create ENI dialog box, configure the parameters that are described in the following table.
Parameter
Description
ENI Name
Enter a name for the ENI.
VPC
Select a VPC. If you want to bind the created ENI to an instance, select the VPC in which the instance resides. After you create an ENI, you cannot change the VPC to which the ENI belongs.
NoteAn ENI can be bound to only an instance that is in the same VPC as the ENI.
VSwitch
Select a vSwitch. If you want to bind the created ENI to an instance, select a vSwitch that is in the same zone as the instance. After you create an ENI, you cannot change the vSwitch to which the ENI is connected.
NoteAn ENI can be bound to only an instance that is in the same zone as the ENI. The instance and the ENI can be connected to different vSwitches.
Security Group
Select security groups in the selected VPC. You can specify up to five security groups.
NoteBasic security groups and advanced security groups cannot be selected at the same time.
Primary Private IP
Optional. Enter an IPv4 address as the primary private IP address of the ENI. The IPv4 address must be an idle IP address within the CIDR block of the selected vSwitch. If you do not specify an IPv4 address, an idle private IPv4 address is automatically assigned to the ENI after the ENI is created.
Secondary Private IP Addresses
Optional. Specify secondary private IP addresses for the ENI.
Not set: No secondary private IP addresses are assigned to the ENI.
Auto: Enter an integer in the range of 1 to 9 as the number of secondary private IP addresses that you want to assign to the ENI. The system automatically assigns the specified number of idle IP addresses from within the CIDR block of the selected vSwitch to the ENI.
Manual: Manually assign secondary private IP addresses to the ENI. You can specify up to nine secondary private IP addresses.
Description
Optional. Enter a description that can help you manage the ENI.
Resource Group
Optional. Select a resource group. Resources that are owned by multiple accounts and assigned to multiple projects can be added to resource groups for easy management. For more information about resource groups, see Resource groups.
Tag
Optional. Select one or more tags to add to the ENI for easy search and management. For more information about tags, see Overview.
Click OK.
If Available is displayed in the Status column of the ENI on the Network Interfaces page, the ENI is created.
What to do next
After you create an ENI, you can bind the ENI to an instance. For more information, see Bind an ENI.