Update docs/upgrade/v1-5-x-to-v1-6-0.md

Co-authored-by: Jillian Maroket <[email protected]>
Signed-off-by: Renuka Devi Rajendran <[email protected]>

Author: rrajendran17

docs/upgrade/v1-5-x-to-v1-6-0.md

@@ -203,7 +203,11 @@ Before upgrading to v1.6.x, perform the following steps:
     bridge vlan show
     ```
 
-For example, consider user having a mgmt interface configured with vlan `2021` during installation and have the following under `/oem/99_vlan-ifcfg.yaml`
+#### Upgrade Scenario
+
+Starting with v1.6.0, only the primary VLAN ID is assigned to the `mgmt-br` bridge and the `mgmt-bo` interface, rather than the entire VLAN ID range (2–4094). Consequently, communications that use secondary VLANs on the `mgmt` interface are affected.
+
+In the following example, a v1.5.x cluster was initially installed with a [primary VLAN interface](../install/harvester-configuration.md#installmanagement_interface) (VLAN ID: `2021`). To add a secondary VLAN interface (VLAN ID: `2113`), the `/oem/99_vlan-ifcfg.yaml` file  was created on the management hosts with the following contents:
 
 ```
 stages: