diff --git a/docs/guides/deploy-guide/examples/cloud-in-a-box.md b/docs/guides/deploy-guide/examples/cloud-in-a-box.md
index 32749f9579..54e1c49c28 100644
--- a/docs/guides/deploy-guide/examples/cloud-in-a-box.md
+++ b/docs/guides/deploy-guide/examples/cloud-in-a-box.md
@@ -297,7 +297,8 @@ Settings for eno7:
 ```
 
 Now this device is made permanently known in the network configuration. Select the MTU
-accordingly. For 1 GBit rather `1500` than `9100`.
+accordingly. For 1 GBit rather `1500` than `9100`. The 2nd network interface should be
+configured without IP configuration (neither static nor DHCP).
 
 * `/opt/configuration/inventory/group_vars/generic/network.yml`
 * `/opt/configuration/environments/manager/group_vars/manager.yml`