I am working on OpenStack single-stack IPv6 support in Ignition. To validate the new feature, I'm testing single-stack IPv6 support in OpenStack using:

• A custom Fedora CoreOS (FCOS) image (with my Ignition changes)

• A standard RHEL 9.2 cloud image

In both cases, I can’t SSH into the instance when it’s using only IPv6. However, when using dual-stack (IPv4 + IPv6), SSH works fine with both protocols. 

The error that I get in both cases:

"port 22: Connection timed out"

Questions: 

• Is this a known limitation with single-stack IPv6 or a expected behaviour?

• Any ideas how could I debug this problem? 

Environment:

• OpenStack Version: Openstack 5.5.2
• Fedora CoreOS Version: Custom version with ignition changes overrides
• RHEL Version: 9.2
• Security Groups: Default security group used

Test Summary:

Thanks for your time, I am free to discuss or if you need more information about my enviroment.