Change the network type of an ALB instance

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ALB instances support Internet-facing and internal-facing network types. Change the network type to control public or VPC-only access.

Network types

Network type

IP addresses assigned per zone

Access scope

Private

Private IPv4 address only (IPv4); Private IPv4 address + IPv6 address (dual-stack)

Resources within the same VPC

Public

Public IPv4 address + private IPv4 address (IPv4); Public IPv4 address + private IPv4 address + IPv6 address (dual-stack)

Internet and VPC resources

Internet-facing ALB instances use elastic IP addresses (EIPs) by default, which incur instance and data transfer fees. To use an Anycast EIP instead, see Associate Anycast EIPs with an ALB instance.

IP versions

ALB supports IPv4 and dual-stack networking.

IP version

Clients

Backend servers

IPv4

IPv4 addresses only (example: 192.0.2.1)

ECS instances, elastic network interfaces (ENIs), elastic container instances, IP addresses, Function Compute functions

Dual-stack

IPv4 and IPv6 addresses (example: 192.168.0.1, 2001:db8:1:1:1:1:1:1)

ECS instances, ENIs, elastic container instances, IP addresses. Function Compute is not supported.

Note

To add an IPv6 address to an IP-type server group on a dual-stack ALB instance, use an upgraded ALB instance.

ALB uses Alibaba Cloud DNS domain names. Map custom domains to the ALB domain name with CNAME records. For details, see Configure a CNAME record for an ALB instance.

Public IP address types

ALB supports two types of public IP addresses:

Type

Description

EIP

A public IP address that you can independently purchase and associate with VPC-based CLB instances, internal-facing ALB instances, or Internet NAT gateways. What is EIP?

Anycast EIP

A public IP address with global anycast capabilities. What is Anycast EIP?

Note

For a comparison of EIPs and Anycast EIPs, see Anycast EIP vs. EIP.

Prerequisites

Ensure the following:

Switch an IPv4 ALB instance from internal to Internet-facing

After this change, assign EIPs or Anycast EIPs to the ALB instance. Internet data transfer fees apply. EIP billing, Anycast EIP billing.

  1. Log on to the ALB console.

  2. In the top navigation bar, select the region of the ALB instance.

  3. On the Instances page, click the ID of the internal-facing ALB instance.

  4. On the Instance Details tab, find Network Type in the Basic Information section and click Change Network Type next to IPv4:Private.

  5. In the Change Network Type dialog box, select an IP Type and assign public IP addresses. Option A: Assign EIPs Option B: Assign Anycast EIPs For Anycast EIP limits and procedures, see Associate Anycast EIPs with an ALB instance.

    1. Set IP Type to EIP.

    2. Select Purchase EIP from the Assign EIP drop-down list, or select an existing Anycast EIP, and click OK.

      Note
      • Assign an EIP to each zone in the list.

      • To use an EIP with a specific IP address, replace the EIP by adding or removing zones. Modify the configurations of ALB instances.

      • Changing the network type automatically releases or disassociates all assigned EIPs. Released EIPs cannot be restored.

        • View EIP details in the EIP console.

        • Purchased EIPs use pay-as-you-go billing with pay-by-data-transfer metering, BGP (Multi-ISP) lines, and Anti-DDoS Origin Basic protection.

      Note
      • Assign Anycast EIPs to all zones in the list.

      • Switching an ALB instance to internal-facing or releasing it automatically disassociates and releases associated Anycast EIPs.

      • View Anycast EIP details in the Anycast EIP console.

  6. Click OK.

  7. Return to the Instance Details tab and verify the Network Type value. The change takes about 1 minute. When IPv4 shows Public, the ALB instance is Internet-facing.

Switch an IPv4 ALB instance from Internet-facing to internal

Warning

After this change, all public IP addresses are disassociated from the ALB instance and its DNS records are updated. This disrupts Internet-facing traffic.

  1. Log on to the ALB console.

  2. In the top navigation bar, select the region of the ALB instance.

  3. On the Instances page, click the ID of the Internet-facing ALB instance.

  4. On the Instance Details tab, find Network Type in the Basic Information section and click Change Network Type next to the public IPv4 address.

  5. In the confirmation message, review the impacts and click OK.

  6. Return to the Instance Details tab and verify the Network Type value. The change takes about 1 minute. When IPv4 shows Private, the ALB instance is internal-facing.

Switch a dual-stack ALB instance to public IPv6

To switch from private IPv4 to public IPv4 on a dual-stack instance, follow the same steps as Switch an IPv4 ALB instance from internal to Internet-facing.

The following steps describe how to switch to public IPv6.

Note

Switching to public IPv6 enables Internet bandwidth for the IPv6 gateway. This bandwidth is billed and automatically enabled or disabled based on the ALB network type. See IPv6 gateway billing.

  1. Log on to the ALB console.

  2. In the top navigation bar, select the region of the ALB instance.

  3. On the Instances page, click the ID of the internal-facing ALB instance.

  4. On the Instance Details tab, find Network Type in the Basic Information section and click Change Network Type next to the IPv6 address.

  5. In the Change Network Type message, review the impacts and click OK.

    Note

    If the VPC lacks an IPv6 gateway, follow the console prompts to create one.

  6. Return to the Instance Details tab and verify the Network Type value. The change takes about 1 minute. When IPv6 shows Public, the ALB instance supports public IPv6 traffic.

Switch a dual-stack ALB instance to private IPv6

To switch from public IPv4 to private IPv4 on a dual-stack instance, follow the same steps as Switch an IPv4 ALB instance from Internet-facing to internal.

The following steps describe how to switch to private IPv6.

  1. Log on to the ALB console.

  2. In the top navigation bar, select the region of the ALB instance.

  3. On the Instances page, click the ID of the Internet-facing ALB instance.

  4. On the Instance Details tab, find Network Type in the Basic Information section and click Change Network Type next to the IPv6 address.

  5. In the Disable Elastic IPv6 message, review the impacts and click Disable.

  6. Return to the Instance Details tab and verify the Network Type value. The change takes about 1 minute. When IPv6 shows Private, the ALB instance no longer supports public IPv6 traffic.

Limitations

Anycast EIP with ALB

Anycast EIPs can be associated with ALB instances in the following regions:

Area

Regions

China

China (Hong Kong)

Asia Pacific

South Korea (Seoul), Japan (Tokyo), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok)

Europe and Americas

UK (London), US (Virginia), US (Silicon Valley), Germany (Frankfurt)

EIP with ALB

Billing

ALB is billed hourly, rounded up to 1 hour. Network type changes take effect immediately, but the current hour bills at the previous type. See ALB billing.

Change

Operation

Billing impact

Reference

Private IPv4 to public IPv4

Associate an EIP or Anycast EIP

Internet data transfer fees apply

EIP billing, Anycast EIP billing

Public IPv4 to private IPv4

Disassociate EIPs or Anycast EIPs

Check the actual bill for details

-

Private IPv6 to public IPv6

Enable Internet bandwidth for the IPv6 gateway

IPv6 Internet bandwidth fees apply

IPv6 gateway billing

Public IPv6 to private IPv6

Disable Internet bandwidth for the IPv6 gateway

Check the actual bill for details

-

References