> For the complete documentation index, see [llms.txt](https://docs.verifone.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verifone.com/support-nordics/p400-integrated/errors/failed-check-interface-config.md).

# Failed Check Interface Config

What to do when your P400 shows Failed check interface config while connecting to Wi-Fi — update the Wi-Fi security setting.

{% hint style="info" %}
**Use this page when** your terminal shows **Failed check interface config** while connecting to Wi-Fi.
{% endhint %}

<details>

<summary>Keywords</summary>

Also called: failed check interface config, interface config failed, Wi-Fi config error, Wi-Fi won't connect, group cipher. Search terms: failed check interface config, interface, config, Wi-Fi, wifi, group cipher, CCMP, AES, TKIP, authentication.

</details>

## Symptoms

You may see one or more of the following:

* The terminal shows **Failed check interface config** when connecting to Wi-Fi.
* The terminal doesn't show **"Network started"** after you've saved your Wi-Fi settings.

**Why this happens:** the Wi-Fi security setting (called **Group cipher**) on the terminal doesn't match your Wi-Fi network. Changing it to **CCMP (AES)/TKIP** usually fixes this.

## Before you start

To open the menu, press **4** and **6** at the same time, then enter password **1234** and press the **green button**.

## Resolution

{% stepper %}
{% step %}

### Open your saved Wi-Fi network

1. Open the menu.
2. Select **Administration > Settings > Communication**.
3. Select **More > Configuration > Network Interface > Wi-Fi**.
4. Tap your Wi-Fi network (SSID).

<figure><img src="https://2708971099-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fa0qV9Wx6LdSaDc8JrEef%2Fuploads%2F96ubZSbFVeu2kGik7V7I%2Fp400tp-wifi-10-select-network.png?alt=media" alt="Select your Wi-Fi network" width="200"><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Open the security settings

1. Tap **View/Edit**.
2. Tap **Authentication**.

<figure><img src="https://2708971099-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fa0qV9Wx6LdSaDc8JrEef%2Fuploads%2FtFsPH78VqNC6uhweS37a%2Fp400tp-wifi-11-view-edit.png?alt=media" alt="View/Edit option" width="200"><figcaption></figcaption></figure>

<figure><img src="https://2708971099-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fa0qV9Wx6LdSaDc8JrEef%2Fuploads%2FlxpcNTEO9hoWVkNWcwK4%2Fp400tp-wifi-12-authentication.png?alt=media" alt="Authentication option" width="200"><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Change the Group cipher

1. Tap **Group cipher**.
2. Select **CCMP (AES)/TKIP**.
   {% endstep %}

{% step %}

### Save the settings

1. Tap the **back arrow**.
2. Tap **Save**, then **OK**, then **Yes**.

<figure><img src="https://2708971099-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fa0qV9Wx6LdSaDc8JrEef%2Fuploads%2FJJ8nlNHzWRwIsWsB6n5f%2Fp400tp-wifi-14-back-save.png?alt=media" alt="Go back and save" width="200"><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Check the connection

The screen should show **"Network started"** with a **green tick**.

<figure><img src="https://2708971099-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fa0qV9Wx6LdSaDc8JrEef%2Fuploads%2FJILXfNZ82xZMbM6XUuBt%2Fp400tp-wifi-09-network-started.png?alt=media" alt="Network started with a green tick" width="200"><figcaption></figcaption></figure>

✅ **Network started — stop here.** ❌ **Still not connecting — continue to Step 6.**
{% endstep %}

{% step %}

### Check your Wi-Fi network is working

* Try connecting another device, such as your phone, to the same Wi-Fi.
* If you don't have another internet connection, you can test the terminal using your mobile phone's **personal hotspot** — see [How to Set Up Wi-Fi](/support-nordics/p400-integrated/how-tos/how-to-set-up-wi-fi.md).

✅ **Connected — stop here.** ❌ **Still not connecting — continue to Step 7.**
{% endstep %}

{% step %}

### Contact Verifone Support

If the terminal still won't connect, <mark style="color:red;">contact Verifone Support</mark>.
{% endstep %}
{% endstepper %}

**If the terminal shows "Network started".** It's connected and ready to use.

**If it still won't connect.** Contact Support below.

## Still not working?

{% hint style="info" %}
**Still need help? Contact Verifone Support.**

If the steps above haven't resolved the issue, <mark style="color:red;">contact Verifone Support</mark>. Tell us the troubleshooting steps you've already tried — it helps us get you to the right support faster.
{% endhint %}


---

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