Auth0 Forcing IPv4 or IPv6 instead of Dual Stack

Last Updated: Sep 10, 2025

Overview

Auth0 uses IPv4/IPv6 dual stack, meaning requests can be made using either protocol. This article explains whether it is possible to force the use of one protocol over another.

Solution

Auth0 cannot force a device to use a specific protocol. If the device connects with either protocol, it will be allowed, and the IP will be propagated to the applications, such as the IP seen in the logs.

If this is a critical requirement, one workaround would be to use a Self-Managed Custom Domain. In this setup, all requests to Auth0 must come through a customer-provided reverse proxy. This proxy can choose to expose only IPv4 or IPv6 (for example, by exposing only A records and not AAAA), so all requests will be made using that allowed protocol.