diff --git a/docs/getting-started/install-multi-node/README.md b/docs/getting-started/install-multi-node/README.md
index ca0ba8709..3f7d05b03 100644
--- a/docs/getting-started/install-multi-node/README.md
+++ b/docs/getting-started/install-multi-node/README.md
@@ -22,6 +22,7 @@ resources:
 ## Table of Contents
 
 - [Overview](#overview)
+- [Prerequisites](#prerequisites)
 - [Instructions](#instructions)
 - [Troubleshooting](#troubleshooting)
 
@@ -37,6 +38,22 @@ A Spinifex cluster distributes services across multiple servers for high availab
 - UDP port 6081 open between hosts (Geneve tunnels)
 - TCP ports 4222, 4248, 6641, 6642 open between hosts (NATS, OVN)
 
+## Prerequisites
+
+> [!IMPORTANT]
+> **Prerequisite — WAN bridge required on every node.**
+>
+> Before running the installer on any server, that server's WAN interface **must** already be enslaved to a Linux bridge named `br-wan`. The host IP, default route, and DHCP must all live on the bridge — not on the bare NIC.
+>
+> The bootstrap installer does **not** create this bridge for you yet. Running it on a host whose default route is still on a bare NIC will leave the install in a non-working state. Auto-provisioning of `br-wan` will land in the next release.
+>
+> **Verify on every node before continuing:**
+>
+> - `ip -br link show br-wan` — bridge exists and is `UP`
+> - `ip route` — default route's `dev` is `br-wan`
+>
+> **Setup references:** [VPC Networking → Bridge Setup](/docs/vpc-networking#bridge-setup-physical-network-wiring) for the topology.
+
 ## Instructions
 
 ## Step 1. Install Spinifex on Each Server
diff --git a/docs/getting-started/install/README.md b/docs/getting-started/install/README.md
index f5e48427a..7824d248a 100644
--- a/docs/getting-started/install/README.md
+++ b/docs/getting-started/install/README.md
@@ -22,6 +22,7 @@ resources:
 ## Table of Contents
 
 - [Overview](#overview)
+- [Prerequisites](#prerequisites)
 - [Instructions](#instructions)
 - [Troubleshooting](#troubleshooting)
 
@@ -47,6 +48,22 @@ This guide installs Spinifex on a single server using the binary installer. For
 - Viperblock (EBS-compatible block storage)
 - AWS CLI v2
 
+## Prerequisites
+
+> [!IMPORTANT]
+> **Prerequisite — WAN bridge required.**
+>
+> Before running the installer, the host's WAN interface **must** already be enslaved to a Linux bridge named `br-wan`. The host IP, default route, and DHCP must all live on the bridge — not on the bare NIC.
+>
+> The bootstrap installer does **not** create this bridge for you yet. Running it on a host whose default route is still on a bare NIC will leave the install in a non-working state. Auto-provisioning of `br-wan` will land in the next release.
+>
+> **Verify before continuing:**
+>
+> - `ip -br link show br-wan` — bridge exists and is `UP`
+> - `ip route` — default route's `dev` is `br-wan`
+>
+> **Setup references:** [VPC Networking → Bridge Setup](/docs/vpc-networking#bridge-setup-physical-network-wiring) for the topology.
+
 ## Instructions
 
 ## Step 1. Install Spinifex