---
title: "WAN interface missing on Classic VX after full power cycle"
slug: "wan-interface-missing-on-classic-vx-after-full-power-cycle"
updated: 2024-12-19T06:54:25Z
published: 2024-12-19T06:54:25Z
canonical: "docs.telosalliance.com/wan-interface-missing-on-classic-vx-after-full-power-cycle"
---

> ## Documentation Index
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# WAN interface missing on Classic VX after full power cycle

## Scope

This document applies to Classic VX or Classic VX Prime running on the Fanless engine platform

This document will show you how to restore BIOS settings if they become reset

## Problem symptoms

After removing and restoring AC power to the VX engine, you find that the "WAN" interface option is missing. It will be missing from the front panel and missing from the web ui. Only the LAN interface is functional on the VX

## Solution

The CMOS battery is not holding a charge anymore. After the removal of AC power, the BIOS settings get reset to defaults.

There is one setting that needs to be manually turned back on, to allow the "WAN" interface to become usable again

1. Disconnect AC power from the VX
2. Connect a USB keyboard and DVI monitor to the back of the VX
3. Connect AC power to the VX
4. Press DEL key quickly several times until you enter the BIOS config screen
5. Depending on which BIOS/ SOM your classic VX has:

Older BIOS/SOM:

Go to “Integrated Peripherals -> Onboard Device -> Onboard LAN1Controller “ set to Enable

Newer BIOS/SOM:

Go to "Chipset tab -> PCH LAN Controller" Set to Enabled

1. Press F10 to save and restart

This setting will stay in place until AC power is lost again on the unit. Please consider changing the CR2032 CMOS battery, located on the carrier board inside the VX engine