---
title: "Configuring Polycom PC Pass-Through Ethernet Port Mode"
description: "## Overview Polycom IP desktop phones feature an integrated secondary Ethernet port (PC pass-through port) that allows a computer to share a single network drop with the phone. In certain environments, administrators need to disable this port to enforce network…"
url: "https://www.dataphone.cloud/docs/port-mode/"
updated: "2026-10-06"
category: Internal / Tech Support / Polycom
tags:
  - pbx
---

# Configuring Polycom PC Pass-Through Ethernet Port Mode

## Overview

Polycom IP desktop phones feature an integrated secondary Ethernet port (PC pass-through port) that allows a computer to share a single network drop with the phone. In certain environments, administrators need to disable this port to enforce network security policies such as preventing unauthorized personal devices, rogue routers, or unauthorized DHCP servers from being plugged into the network behind the phone.

The provisioning parameter `polycom_pc_port_mode` controls the administrative state of this secondary pass-through port.

## Parameter Reference

| Parameter Name | Allowed Values | Default | Description |
| --- | --- | --- | --- |
| `polycom_pc_port_mode` | `-1`, `0` | `0` | Controls PC pass-through Ethernet port operation. |

### Value Definitions

- **`-1` (Disabled):** Shuts down the secondary PC port completely. Any network device plugged into the back of the phone will lose connectivity.
- **`0` (Auto / Enabled):** Default operational mode. Enables pass-through network bridging to attached devices.

> **Important Note:** Changes to this parameter require the Polycom phone to **reboot and re-provision** before the port state change takes effect.

## Device-Level Configuration Guide

To apply this restriction to a **specific device / extension** without altering global device defaults across the entire tenant:

1. Log in to the administrative portal.
2. Navigate to **Accounts** > **Devices**.
3. Locate and select the target device / extension requiring the configuration.
4. Scroll down to the **Settings** (Custom Device Parameters) section.
5. Create a new custom setting entry:
   - **Name:** `polycom_pc_port_mode`
   - **Value:** `-1` *(to disable)* or `0` *(to enable/restore)*
6. Click **Save Changes**.
7. **Reboot / Re-provision** the target device to apply the configuration.

## Verification & Testing

1. Once re-provisioned, observe the phone status LED during restart.
2. Plug an Ethernet cable into the phone's **PC** port and attach a test laptop/device.
3. Verify that the test device fails to obtain an IP address or link light when set to `-1`.