# Multi-PSK (MDU Shared Key)

Multiple Pre Shared Key is a popular configuration option in Multi Dwelling Unit, dormitory or similar environment where it is costly to implement complex 802.1x security however that same level of per-client security is highly desired.

A SSID when configured for multi-psk can have multiple PSK/VID mappings. Each one of them can be bound to a specific MAC or be a wildcard.

```
            "ssids": [
                {
                    "name": "MDU Wi-Fi",
                    "wifi-bands": [
                        "5G",
                        "2G"
                    ],
                    "bss-mode": "ap",
                    "encryption": {
                        "proto": "psk2",
                        "ieee80211w": "optional",
                        "key": "OpenWifi"
                    },
                    "multi-psk": [
                        {
                            "key": "akey",
                            "vlan-id": 100
                        },
                        {
                            "key": "bkey"
                            "vlan-id": 200
                        }
                    ],
                    "roaming": {
                        "message-exchange": "ds",
                        "generate-psk": true
                    }
                }
            ]
```

{% hint style="info" %}
Note: M-PSK passwords must be unique per `vlan-id` as the device will attempt to match security key to assigned virtual lan. In the above example, a password of `OpenWifi` will match the untagged interface of the SSID and unique password of `"akey"` will match client(s) to virtual lan 100.
{% endhint %}