Stack Preference warning missing from IPv6 modal for dual-stack clusters

[yonasberhe23]

Setup

• Rancher version:v2.14-16b1922c97a15d33e8c7af6ae0a38976abdc53af-head
• Rancher UI Extensions: Dashboard master 4f31d4b
• Browser type & version:

Describe the bug
When creating an EC2 cluster with Enable Dual-Stack checked and Enable IPv6 unchecked, the
IPv6 confirmation modal does not include the Stack Preference warning even though the stack
preference is set to IPv6 — which is incorrect for a dual-stack cluster. The docs state that
stack preference must be set to Dual for dual-stack clusters. The modal should warn the user
until they select Dual.

To Reproduce

1. Navigate to Cluster Management → Create → Amazon EC2
2. In the machine pool, check Enable Dual-Stack
3. Select a dual-stack VPC
4. Leave Enable IPv6 unchecked
5. Select stack preference: IPv6
6. Click Create

Result
When stack preference is set to IPv6, the modal does not include the Stack Preference warning,
giving the user the impression that IPv6 is a valid stack preference for a dual-stack cluster.
Per the Rancher docs,
IPv6 is only correct for IPv6-only clusters — dual-stack clusters must use Dual.

Expected Result
The confirmation modal appears and includes the warning:

"The Stack Preference should be set to "Dual" or "IPv6" to use dual-stack or IPv6-only
networking, respectively."

The warning should be present whenever stack preference is not Dual (for a dual-stack-only
cluster). It should only be dismissed from the modal once the user sets stack preference to Dual.

Screenshots

Screen.Recording.2026-02-26.at.1.16.54.PM.mov

Additional context