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Important: IPv6 Support for Mackerel Web Console and API Endpoints, and Associated Action Required for "IP restriction" Settings

announcement

Thank you for using Mackerel.

We are currently working on IPv6 support for Mackerel. Recently, we announced IPv6 support for external URL monitor, and today we would like to inform you about IPv6 support for the Mackerel web console and API endpoints.

Starting Thursday, May 21, 2026, you will be able to access the Mackerel web console and API endpoints via IPv6 from your environment. As a result, if you are using the "IP restriction" feature in your organization settings, depending on your network environment, you may lose access to Mackerel after the release date if you continue with your current settings.

Please review the details below and take necessary action in advance if applicable.

IP restriction

Overview of IPv6 Support

The following services will become accessible via IPv6:

  • Web Console
    • mackerel.io, kcps-mackerel.io
    • These are the URLs accessed by browsers on devices viewing the Mackerel web console.
  • API Endpoints
    • api.mackerelio.com
    • This is the URL accessed by agents when posting metrics, as well as by customer-created programs that use the API.

The IPv6 address range will be:

  • 2406:da14:f83:2600::/56

There will be no changes to the URLs. After the release, IPv4 or IPv6 will be automatically selected based on your network environment.

Customers Not Affected

If any of the following applies to you, no action is required. You can continue using Mackerel with your current settings:

  • You are not using the "IP restriction" feature.
  • You are using the "IP restriction" feature, but only use IPv4 communication for internet connectivity.

Customers Who May Be Affected

If both of the following apply to you, action is required. Please see the next section for what you need to do:

  • You are using the "IP restriction" feature.
  • You use IPv6 communication for internet connectivity.

Required Actions for Affected Customers

By Thursday, May 21, 2026, please add the IPv6 addresses (or network ranges) of your connection sources to the "IP restriction" settings, in addition to the IPv4 addresses you currently allow. If only IPv4 addresses are allowed, all IPv6-based access will be blocked after the release date.

For instructions on how to add IP addresses to the "IP restriction" feature, please refer to the following pages:

Additional notes on configuration:

  • IPv6 addresses can be specified in "address/prefix length" format (abbreviated notation is allowed).
  • Permission settings for the web console and API are independent. If you configure only one, the other will allow all access.
  • Please note that you will not be able to verify the connection before the release.

Frequently Asked Questions (Q&A)

Q. What should I do if I'm not sure whether I'm using IPv6 communication?

A. You can test using the following methods:

  • To check from your device:
    • Access an IPv6 connection test site (e.g., https://test-ipv6.com/ ) using your browser.
      • If you are not using IPv6, it will display "No IPv6 address detected."
  • To check from your server:
    • Run curl -6 ifconfig.io.
      • If you are not using IPv6, it will return an IPv4 address (x.x.x.x).

Q. What should I do if I'm using the "IP restriction" feature and IPv6 communication, but don't have fixed addresses?

A. You can continue using your current settings by disabling IPv6 communication to Mackerel in your network and using only IPv4 communication.

For example, one method is to configure your DNS server not to return IPv6 addresses for the mackerel.io and api.mackerelio.com domains. The appropriate method and its feasibility depend on your network environment, so please consult with your internal network administrator.

Q. Will this affect agents?

A. This will affect agents if the servers running them communicate via IPv6 and you are restricting "API Access" using the "IP restriction" feature.

Agents use API endpoints to post metrics and perform other operations. Please allow the IPv6 addresses that your agent servers use when accessing Mackerel.

Q. Are there plans to support IPv6 for services other than the web console and API endpoints?

A. At the same time as the web console and API endpoints, the following will also become accessible via IPv6:

However, these are not subject to the "IP restriction" feature, so you do not need to add IPv6 addresses to your permission settings.

  • Trace submission endpoint
    • otlp-vaxila.mackerelio.com
  • Labeled metrics submission endpoint
    • otlp.mackerelio.com
  • SCIM integration endpoint
    • scim.mackerelio.com
  • Mackerel demo experience page
    • play.mackerel.io


If you have any questions about this matter, please contact us through our contact form:

This change is being made to ensure stable service delivery. We appreciate your understanding and cooperation.