## Duplex Mode (Optional)

Duplexing is a performance option that lets you choose how the adapter sends and receives data packets over the network. The adapter can operate at full duplex only when connected to a full duplex 10BASE-T or 100BASE-TX switch, or to another full duplex adapter.

The possible settings for duplexing are:

- Auto (requires a full duplex adapter or switch with auto-negotiation capability). The adapter negotiates with the switch to send and receive packets at the highest rate. This is the default setting. If the switch does not provide auto-negotiation, the adapter runs at half duplex.

- Full duplex (requires a full duplex switch or adapter). The adapter can send and receive packets at the same time. This mode can increase adapter performance capability. If the full duplex switch provides auto-negotiation, the adapter runs at full duplex. If the full duplex switch does not provide auto-negotiation, you need to set the adapter duplex mode manually (see the following sections), because it defaults to half duplex.

- Half duplex. The adapter performs one operation at a time; it either sends or receives.

NOTE

: If an adapter is running at 100 Mbps and half duplex, your potential bandwidth is higher than if you run it at 10 Mbps and full duplex.

### Manually Configuring for Full Duplex

If your switch supports auto-negotiation with the NWay* standard, duplex configuration is automatic and no action is required on your part. However, many currently-installed switches do not support auto-negotiation. Check with your network system administrator to verify whether your switch supports this feature. Most installations require manual configuration to change to full duplex.

Configuration is specific to the driver you’re loading for your network operating system (NOS).

To set up the duplex mode, refer to the section below that corresponds to your operating system.

CAUTION

: Adapter performance may suffer or your adapter may not operate if your switch doesn’t support full duplex and you configure the adapter to full duplex. The switch settings must always agree with the adapter. Also, make sure to always set the speed when you configure duplex.

### Setting Full Duplex in Windows 95/98/NT/2000

While running Windows:

> 1. Double-click the PROSet icon from the Control Panel.

> 2. Click the Advanced Tab.

> 3. Select Duplex.

> 4. In the Duplex Mode list box, click Full-Duplex.

> 5. Click OK.

> 6. Restart your computer if prompted.

### Setting Full Duplex in DOS, ODI, NDIS 2.01 Clients

For each adapter, edit the NET.CFG or PROTOCOL.INI file. If editing the NET.CFG file, add the following keywords to the Link Driver section. For the PROTOCOL.INI file, add these keywords anywhere:

FORCEDUPLEX 2

SPEED 100 (or 10 if 10BASE-T)

### Setting Full Duplex in NetWare Servers

For each adapter in AUTOEXEC.NCF, edit the LOAD command and add the following options (you must include the equal sign for servers):

FORCEDUPLEX=2

SPEED=100 (or 10 if 10BASE-T)