4-2 Dell OptiPlex GXa Mini Tower Systems Reference and Installation Guide
A green link integrity indicator lights up when there is a
good connection between the network and the NIC. When the green indicator is off, the computer is not
detecting a physical connection to the network.

Figure 4-1. I/O Ports and Connectors

Network Cable Requirements
Your computer’s NIC connector (an RJ45 connector
located on the back panel) is designed for attaching an
unshielded twisted pair (UTP) Ethernet cable. Press one
end of the UTP cable into the NIC connector until the
cable snaps securely into place.
Connect the other end of the cable to an RJ45 jack wall
plate or to an RJ45 port on a UTP concentrator or hub,
depending on your network configuration. Observe the
following cabling restrictions for 10BASE-T and
100BASE-TX networks.
•For 10BASE-T networks, use Category 3 or greater
wiring and connectors.
•For 100BASE-TX networks, use Category 5 wiring
and connectors.
•The maximum cable run length (from a workstation
to a concentrator) is 328 feet (ft) (100 meters [m]).
•The maximum number of workstations (not counting
concentrators) on a network is 1024.
•For 10BASE-T networks, the maximum number of
daisy-chained concentrators on one network segment
is four.
Configuring the NIC
This subsection provides instructions for configuring the
computer’s integrated, 10/100-Mbps 3Com NIC under
the following operating systems:
•Microsoft Windows NT 4.0
•Microsoft Windows NT 3.5x
•Microsoft Windows for Workgroups
•Microsoft Windows 95
•MS-DOS
NOTE: The NIC drivers for systems running a Dell-
installed Windows NT 4.0 or Windows 95 operating
system are automatically detected and installed. Instruc-
tions for reinstalling the NIC driver for Windows NT and
Windows 95 Service Release 1 and Service Release 2 are
included later in this subsection.
Windows NT 4.0 NIC
The Windows NT 4.0 operating system automatically
detects and installs the NIC driver. To reinstall the driver,
complete the following steps:
1. Use the Dell Program Diskette Maker (located in
the Dell Accessories folder) to make a diskette
copy of the NIC drivers installed on your hard-
disk drive.
keyboard
connector
mouse
connector
serial port 2
connector
USB
connectors
parallel port
connector
optional integrated
NIC connector
line-out jack
microphone jack
video connector
line-in jac
k
activity indicator
link integrity
indicator
serial port 1
connector
CAUTION: To avoid line interference, voice and
data lines must be in separate sheaths.