---
title: Fastly-Force-Shield
summary: null
url: >-
  https://www.fastly.com/documentation/reference/http/http-headers/Fastly-Force-Shield
---

In most cases, Fastly will relay requests from the first server that handles the request to a second server that acts as the primary storage location for the resource being requested.  This process is called [clustering](https://www.fastly.com/documentation/guides/vcl/clustering/).  If a service configuration executes a `restart` during request or response processing, the clustering mechanism is automatically disabled.  This header exists to re-enable it if desired.

```vcl context="vcl_recv { ... }"
set req.http.Fastly-Force-Shield = "1";
```

> **WARNING:** Despite the name, this header has nothing to do with [shielding](https://www.fastly.com/documentation/guides/concepts/shielding/).