You have received a Marvis Actions Missing VLAN notification. In this scenario, where is the problem?

The "Missing VLAN" Marvis Action is triggered when a client fails to obtain an IP address because the VLAN associated with their WLAN is not present on the access point's (AP) uplink. This indicates a misconfiguration on the network switch. Specifically, the switch port to which the AP is connected is not configured to trunk or allow the required VLAN. As a result, the AP cannot forward the client's traffic onto the correct network segment, leading to a connectivity failure that Marvis identifies as a missing VLAN on the switch.

A. The gateway is missing the VLAN: While a gateway misconfiguration can cause network issues, this specific Marvis action isolates the problem to the Layer 2 link between the AP and the switch.

B. An access point is missing the VLAN: The AP is correctly configured with the VLAN via the WLAN settings; the problem is that the switch is not passing the VLAN traffic to the AP.

C. A client is missing the VLAN: Clients are generally unaware of infrastructure VLANs. The issue is a network configuration problem, not a client-side setting.

1. Juniper Mist Documentation, "Marvis Actions for Wireless": In the section for "Missing VLAN," the documentation states, "The root cause is a switch port misconfiguration. The switch port that the AP is connected to is not configured to pass the VLAN traffic for the WLAN the client is trying to connect to." This directly identifies the switch as the location of the problem.

2. Juniper Mist Documentation, "Marvis - Action Dashboard": This guide describes the "Missing VLAN" action as follows: "Identifies the APs that are connected to a switchport that is missing a vlan configuration." This confirms the issue lies with the switchport configuration.