> For the complete documentation index, see [llms.txt](https://platform9.com/kb/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://platform9.com/kb/pmo/how-to/instance-creation-fails-with-error-timeout-waiting-for-vif-plug.md).

# Instance Creation Fails with Error "Timeout Waiting For Vif Plugging Callback

## Problem

* Instance creation fails for one or more networks
* The below error is observed in the UI or logs

{% tabs %}
{% tab title="None" %}

```none
WARNING nova.virt.libvirt.driver [req-[uuid] [user@dmoain.com] CT] [instance: [instance-uuid]] Timeout waiting for vif plugging callback for instance [instance-uuid]
```

{% endtab %}
{% endtabs %}

## Environment

* Platform9 Managed OpenStack v4.0 and Higher

## Cause

This can happen when one or more DHCP agents associated with the network are not running due to various reasons like the host being offline. You may verify the state of the DHCP agent by running the Openstack CLI command

{% tabs %}
{% tab title="None" %}

```none
# openstack network agent list
```

{% endtab %}
{% endtabs %}

If the host is reporting as connected, please check the */var/log/pf9/pf9-neutron-dhcp-agent.log* for any errors.

## Resolution

1. If the hosts with DHCP agent roles are online and you observe errors in the DHCP agent logs on the hosts, as a workaround you could disable the DHCP agent from older hosts and enable it on the other hosts in the environment. This can be done from the UI as well.

<figure><img src="/files/OUJFTUwQDf9ZPS9gOqsP" alt="mceclip0.png"><figcaption><p>mceclip0.png</p></figcaption></figure>

2. After enabling the DHCP on a new host, verify that the new DHCP agent has come up with the command executed in Step 1. Try instance creation and check if it still fails.
3. If you are still encountering any errors, please log a ticket with [Platform9 support](https://github.com/platform9/pcd-docs-gitbook/blob/main/kb/managed-openstack/support.pf9.io)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://platform9.com/kb/pmo/how-to/instance-creation-fails-with-error-timeout-waiting-for-vif-plug.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.