# Set Up Speed and Duplex

| NOTE: This section applies to copper connections only. Fiber-based adapters operate at full-duplex and gigabit only.
| CAUTION: By default, Intel adapters using RJ-45 connections are set to auto negotiate with their link partners. Manually forcing speed and duplex should be done when forcing the link partner.

In the default mode, Intel network adapters using RJ-45 connections will attempt to auto negotiate with their link partners to determine the best setting. If auto negotiation fails and no link is established with the link partner, you may need to manually configure the adapter and link partner to the identical setting to establish link and pass packets. See the instructions below for specific steps.

The possible settings available when auto negotiation is disabled are:

10 Mbps, half duplex | 10 Mbps, full duplex
100 Mbps, half duplex | 100 Mbps, full duplex

The setting you choose must be matched by the link partner.

## Manually Configuring Duplex and Speed Settings

If your switch supports the NWay* standard and is set up to auto-negotiate, full-duplex is automatic and no action is required on your part. Not all switches support auto-negotiation. Check with your network system administrator to verify whether your switch supports this feature.

Configuration is specific to the driver you’re loading for your operating system.

To set a specific Link Speed and Duplex mode, refer to the section below that corresponds to your operating system.

| CAUTION: The settings at the switch must always match the adapter settings. Adapter performance may suffer or your adapter may not operate if you configure the adapter differently from your switch.

## Windows XP

The default setting is for auto negotiation to be enabled. Change this only if you cannot obtain link with your switch.

| NOTE: Gigabit adapters will not operate at gigabit speed (1000 Mbps) if you disable auto negotiation.

If you need to manually change the settings:

1. Double-click the Intel® PROSet II icon from the Control Panel or System Tray.

2. Click the Link Config tab and highlight the desired adapter in the left window (see example below).

3. Click the Disabled button and then set the speed and duplex parameters that match your switch.

4. Click OK to finish.

5. Restart your computer if prompted.

If Auto Negotiation is disabled, this lets you specify Forced Speed and Duplex. In this situation, the Negotiable Speeds and Duplexes checkboxes are disabled.

If Auto Negotiation is enabled, this enables the Negotiable Speeds and Duplexes checkboxes allowing specific speed advertisement, and disables the Forced Speed and Duplex selection buttons.

## Linux

See the Linux documentation in this software package.

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