---
name: satellite-ts-host-expired-token
title: Why is my host attach failing with error message `A0029` `Access denied to specified controller`?
description: Troubleshoot and resolve host attach failures with error A0029 caused by an expired `host_queue_token` value in your Satellite location.
last-updated: 2026-08-10
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/satellite?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

# Why is my host attach failing with error message `A0029` `Access denied to specified controller`?
{: #ts-host-expired-token}

Troubleshoot and resolve host attach failures with error A0029 caused by an expired `host_queue_token` value in your Satellite location.
{: shortdesc}

When you run the attach host script, your hosts are not attaching and you get a error message similar to the following example.
{: tsSymptoms}



```sh
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: + echo '{"incidentID":"a11babcd-202d-4c97-111a-1111abdcdf11","code":"A0029","description":"Access denied to specified controller.","type":"Authentication"}'
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: {"incidentID":"f97fabec-602d-4c97-946a-8699ccdcdf75","code":"A0029","description":"Access denied to specified controller.","type":"Authentication"}
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: + echo 401
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: 401
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: + [[ 401 -ne 201 ]]
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: + echo 'Error [HTTP status: 401]'
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: Error [HTTP status: 401]
Nov 07 18:19:56 tl2vdu ibm-host-attach.sh[5562]: + exit 1
Nov 07 18:19:56 tl2vdu systemd[1]: ibm-host-attach.service: Main process exited, code=exited, status=1/FAILURE
Nov 07 18:19:56 tl2vdu systemd[1]: ibm-host-attach.service: Failed with result 'exit-code'.
```
{: screen}


Your host attach script is older than one year and the `HOST_QUEUE_TOKEN` value expired.
{: tsCauses}


[Download a new copy](https://cloud.ibm.com/docs/satellite?topic=satellite-host-attach-download&format=markdown) of your host attach script or ignition file from your location.
{: tsResolve}

When your host attach script expires, your unassigned hosts enter a `Unresponsive` status. For more information, see [Why do my unassigned hosts have an `Unresponsive` status](https://cloud.ibm.com/docs/satellite?topic=satellite-ts-host-unassigned-unknown&format=markdown)?
{: note}