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Elastic Compute Service

IP Address

IP address overview

Description

After an IP address is assigned to a network interface, other resources in the network can use this IP address to accurately locate and communicate with the ECS instance associated with the network interface.

tip

IPv6 gateways and Dual-Stack VPC are currently in beta. Only accounts that have completed enterprise authentication can apply for a trial. If you need a trial, contact your account manager.

Classification

Category	Description
Primary private IP address	The primary private IP address is a private IPv4 address that must be assigned to a network interface upon creation. It does not support active reclaim, and its lifecycle is tied to that of the network interface.
Secondary private IP address	Except for the primary private IP address, any other IPv4 or IPv6 address assigned to the network interface is referred to as a secondary private IP address.

Comparison between IPv4 and IPv6 addresses

The following table shows the comparison between VolcanoEngine IPv4 and IPv6 addresses.

Item	Private IPv4 address	Public IPv4 address	IPv6 address
Address length	32-bit	32-bit	128-bit
Uniqueness	Repeatable	Globally unique	Globally unique
Internet access	No	Yes	Internet access is supported after you enable IPv6 Internet bandwidth.
Assignment method	Assigned from the IPv4 CIDR block of the VPC.	Assigned by VolcanoEngine based on user applications.	Assigned from the IPv6 CIDR block of the VPC.
Network Interface address restriction	The number of IPv4 addresses that can be assigned to a network interface is limited by the ECS instance type. For details, see Limits.	You can associate each private IPv4 address of a network interface with a public IPv4 address.	The number of IPv6 addresses that can be assigned to a network interface is limited by the ECS instance type. For details, see Limits.
Chargeable	No	Yes	If IPv6 Internet bandwidth is not enabled, you are not charged. Otherwise, you are charged.

Limits

The number of private IPv4 addresses and private IPv6 addresses that you can assign to the primary network interface or to any secondary network interface mounted to an ECS instance is limited by the private IP address quota of a single network interface. The quota is determined based on the ECS instance type.

For example, the private IP address quota of a single network interface is six for an instance whose type is ecs.g3i.large. That is, you can assign up to six private IPv4 addresses (including the primary private IPv4 address) and six private IPv6 addresses to the primary or secondary network interface of an ECS instance whose type is ecs.g3i.large.

You can manually assign up to nine secondary private IPv4 addresses and ten private IPv6 addresses to a secondary network interface that has never been mounted to an ECS instance.

You can associate each IPv4 address of a network interface with an EIP.

By default, IPv6 addresses of a network interface only support private network communication. To access the Internet over IPv6, you need to first enable IPv6 Internet access.

Procedure

IPv4

IPv6

Assign IPv4 addresses.

Configure IPv4 addresses.

View IP addresses.

(Optional) Associate EIPs

Last updated: 2026.06.18 17:49:50