topic Re: ACI Simulator Always On - Issues when using Terraform only in DevNet Sandbox

ACI Simulator Always On - Issues when using Terraform only

Dmac28 — Thu, 09 Apr 2026 12:39:48 GMT

Hi tehe team,

I've been working all morning with no issues pushing small changes to the simulator. I have not changed the credentials but now I only get the following error:

│ Error: Unable to authenticate. Please check your credentials
│
│ with data.aci_l3_domain_profile.nsxt_ext_domain,
│ on sources.tf line 9, in data "aci_l3_domain_profile" "nsxt_ext_domain":
│ 9: data "aci_l3_domain_profile" "nsxt_ext_domain" {
│
╵│ err: Unable to authenticate. Please check your credentials. Please report this issue to the provider developers.

With the same creds I can authenticate no issues to the WebUI.

Is there a reason for this?

Thanks for your help in advance.

Re: ACI Simulator Always On - Issues when using Terraform only

sekillinick1 — Thu, 09 Apr 2026 12:57:54 GMT

Hi!

It looks like the issue might not be with your credentials themselves since you can log in via WebUI. A few things to check for Terraform/ACI provider authentication:

Session expiration / token issues – Sometimes API tokens or sessions expire even if the password hasn’t changed. Try refreshing your token or reinitializing the provider.

Provider version changes – Did the Terraform provider or your ACI module update recently? Certain versions may introduce stricter authentication checks.

Environment variables/config – Make sure the credentials used in Terraform are exactly the same as WebUI (no extra spaces, correct case, correct environment variable names).

API access permissions – WebUI login might work, but API access could be restricted if roles/permissions are changed.

If none of these work, reporting the issue to the provider developers as the error suggests is a good next step.

Has anyone else faced sudden Terraform ACI authentication failures despite working credentials?

Re: ACI Simulator Always On - Issues when using Terraform only

Dmac28 — Thu, 09 Apr 2026 14:30:15 GMT

It is working now. I didn't make any changes at all and retried after a couple of hours. I imagine the server was too congested.

Thanks