Elastic Network Interface (ENI) is an elastic interface for network access that binds Cloud Virtual Machine (CVM) servers on a Virtual Private Cloud (VPC) for seamless migration among multiple CVM servers. Multiple ENIs can be bound to one CVM server to create a highly available network.
An ENI is part of a subnet, which is part of a VPC, which in turn is part of an availability zone. An ENI can only be associated with a CVM instance in the same availability zone. Multiple ENIs can be associated with the same CVM instance. The specific number depends on the specification of the CVM.
The number of ENIs a CVM instance can be associated with and the number of private IPs an ENI can be associated with depend on the CPU and memory configurations. They are shown in the following table:
The number of IP addresses bound to a single ENI only represents the upper limit of IP addresses that ENIs can be bound to, not the available EIP quota. For the EIP quota of your account, please refer to EIP use limits.
|CVM specification||Number of ENIs||Number of private IPs|
|CPU: 1 core Memory: 1 GB||2||2|
|CPU: 1 core Memory: > 1 GB||2||6|
|CPU: 2 cores||2||10|
|CPU: 4 cores Memory: < 16 GB||4||10|
|CPU: 4 cores Memory: > 16 GB||4||20|
|CPU: 8 - 12 cores||6||20|
|CPU: > 12 cores||8||30|
The following is a list of APIs related to ENI and CVM. For more information, refer to Overview of ENI APIs.
|Create ENI||[CreateNetworkInterface] (https://intl.cloud.tencent.com/document/api/215/15818?from_cn_redirect=1)||Creates an ENI|
|Apply for private IPs||AssignPrivateIpAddresses||Applies for private IPs for an ENI|
|Bind an ENI to a CVM instance||AttachNetworkInterface||Binds an ENI to a CVM instance|