> For the complete documentation index, see [llms.txt](https://help.verkada.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.verkada.com/new-alarms/configuration/alarm-panel-as-a-lan-expander.md).

# Alarm Panel as a LAN Expander

Expander Mode allows a second alarm panel to forward signals from its connected wired and wireless devices to the primary panel over the LAN. When a second supported panel is added to an alarm site, it automatically enters Expander Mode.

This is designed for sites with multiple buildings, such as schools, manufacturing campuses, and business complexes, where the buildings share a network but do not have conduit between them. Devices connected to the expander can be added to and managed from the same alarm site.

{% hint style="warning" %}

* An expander panel does not require an additional license.
* The expander panel inherits the site settings from the primary panel.
  {% endhint %}

***

### When to use Expander Mode

* Use Expander Mode when buildings share a single address, a single set of monitoring requirements, and a single operational identity. 
* Use separate alarm sites for buildings that are independent locations with their own addresses and dispatch requirements.

### Requirements

* Both panels must be added to the same alarm site in Command.
* Both panels must be connected to the same LAN. 
* The expander panel must be a BP52 or a BP42.

{% hint style="danger" %}

* Cellular backup is not supported on expander panels.
* Battery backup is supported. However, Command does not currently display the battery charge or indicate when an expander panel is running on battery power.
* BP32 alarm panel is not supported as an expander panel. 
  {% endhint %}


---

# 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 by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://help.verkada.com/new-alarms/configuration/alarm-panel-as-a-lan-expander.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

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.