diff --git a/content/manuals/build-cloud/setup.md b/content/manuals/build-cloud/setup.md
index cbf4098c7b..9d8ef75ab0 100644
--- a/content/manuals/build-cloud/setup.md
+++ b/content/manuals/build-cloud/setup.md
@@ -70,6 +70,16 @@ The builder has native support for the `linux/amd64` and `linux/arm64`
 architectures. This gives you a high-performance build cluster for building
 multi-platform images natively.
 
+## Firewall configuration
+
+To use Docker Build Cloud behind a firewall, ensure that your firewall allows
+traffic to the following addresses:
+
+- 3.211.38.21
+- https://auth.docker.io
+- https://build-cloud.docker.com
+- https://hub.docker.com
+
 ## What's next
 
 - See [Building with Docker Build Cloud](usage.md) for examples on how to use Docker Build Cloud.