Intel 10/100 manual Configuring a port for full duplex, Recommended environments

C H A P T E R 2 Intel Express 10/100 Fast Ethernet Switch

NOTE

You must have a point-to- point connection to establish a full-duplex connection (shared hubs/repeaters/ concentrators aren’t capable of full duplex). Additionally, both points of the connection must be configured for full duplex.

NOTE

Setting a port to full duplex automatically disables flow control. Since collisions don’t occur on a full-duplex link, flow control isn’t possible.

One exception is between two Express 10/100 switches. Special information is added to packets traveling between switches to accomplish this.

The Coll/Fdpx LED is solid green when the port is configured for full duplex.

Configuring a port for full duplex

Configuring a port for full duplex allows the switch to send and receive packets simultaneously with the destination device. To establish a full-duplex link, the switch and the destination device both must be configured for full duplex.

Additionally, the link must be to a switch, workstation, or server. You can’t establish a full-duplex link to a device that broadcasts incoming packets to every port on the device. This excludes shared hubs, repeaters, or concentrators from using full duplex.

Commands used

get-port-cfg

set-speed-sel <port> {asense10100} set-port-dplex <port> {fullhalf}

Recommended environments

Full duplex is best when two devices exchange information to and from each other (such as a file server). In the diagram on page 20, the Payroll and Finance 100 Mbps workgroups frequently copy files to and from the file server on port 5.

To configure a port for full duplex

1Configure the device on the other end for full duplex. In the diagram on page 20, you’d configure the adapter in the file server for full duplex.

2Get the current port settings using the get-port-cfgcommand. If the port is set to autosense the speed (asense is the default) then you must set the speed to either 10 or 100. This example sets port 5 to 100 Mbps.

set-speed-sel 5 100

3Set the port to full duplex. (This command fails is you haven’t manually changed the speed to 10 or 100).

set-port-dplex 5 full

4Check the Coll/Fdpx LED. It should be solid green, indicating full duplex.

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