PCI 100Base-T Network Adapter Installation and Service Guide (32650-90904)

6 Chapter1

PCI 10/100Base-TX/3000 Quick Installation

Notes on Manual Speed and Duplex Mode Conﬁguration

Notes on Manual Speed and Duplex Mode

Conﬁguration

Ensure that the speed, duplex mode, and autonegotiation of the

associated switch are conﬁgured the same as in the NMMGR

conﬁguration for the PCI 10/100Base-TX card. If the switch supports

autonegotiation on the ports connected to the cards, this should be

enabled as explained in “Notes on Autonegotiation and Autosensing.”

The NMMGR default is autonegotiation, so if the switch does not

support it, you will need to change settings before using the link.

NOTE

Operation of a link under mismatched host/hub port setting conditions

may result in poor throughput, disconnects and/or application errors.

Because the PCI 10/100Base-TX LAN card and Core I/O card LAN port

support autonegotiation, you should not normally need to manually set

the duplex mode when connected to a switch port which is also enabled

for autonegotiation. Sometimes you may need to manually set the

duplex mode of the card — for example, if the switch is operating at full

duplex but does not autonegotiate.

Full-duplex mode is most commonly found in switches rather than

hubs. It may be found in either 10 Mbit/s or 100Mbit/s switch devices.

Full-duplex mode may provide a throughput advantage under some

circumstances, but the degree of the advantage is application-

dependent.

To manually set the duplex mode of the PCI card, refer to the link

conﬁguration screen in the active NMCONFIG network conﬁguration

ﬁle, using NMMGR to access the conﬁguration data and make changes.

The PCI 10/100Base-TX card and the Core I/O card LAN port support

both half- and full-duplex operation.