10/100/1000 Ports; Appendix B Connector And Cable; Connecting To 10Base-T And 100Base-Tx Devices - Cisco WS-C2950T-48-SI Hardware Installation Manual

Connector Specifications
Use a straight-through cable to connect two ports only when one port is designated with an X. Use a
Note
crossover cable to connect two ports when both ports are designated with an X or when both ports do
not have an X.
Figure B-1

10/100/1000 Ports

The 10/100/1000 Ethernet ports on Catalyst 2950T-24, Catalyst 2950T-48-SI, and Catalyst 2950
Long-Reach Ethernet (LRE) switches use standard RJ-45 connectors.
On the Catalyst 2950 LRE switches, the four input uplink ports are bundled as two logical ports, each
Note
consisting of a copper 10/100/1000 port and a fiber-optic small form-factor pluggable (SFP) module slot,
respectively.
Within each logical port, you can use only the copper or the fiber-optic port at one time. If the Catalyst
2950 LRE switch senses more than two connections for both logical ports, the switch chooses the
fiber-optic connections over the copper connections in default operation.
See the

Connecting to 10BASE-T and 100BASE-TX Devices

When connecting the ports to 10BASE-T and 100BASE-TX devices, such as servers, workstations, and
routers, you can use a two or four twisted-pair, straight-through cable wired for 10BASE-T
and100BASE-TX.
Figure B-12
When connecting the ports to 10BASE-T- and 100BASE-TX devices, such as switches or repeaters, you
can use a two or four twisted-pair, crossover cable.
cable schematics.
You can use Category 3, 4, or 5 cabling when connecting to 10BASE-T devices. You must use Category
5 cabling when connecting to 100BASE-TX devices.
Catalyst 2950 Switch Hardware Installation Guide
B-2
10/100 RJ-45 Pinouts
Pin Label
1 RD+
2 RD-
3 TD+
4 NC
5
NC
6 TD-
7 NC
8 NC
"SFP Module Slots" section on page 1-11
Figure B-10
shows the four twisted-pair, straight-through cable schematics.
Figure B-13 shows the four twisted-pair, crossover cable schematics.
1 2 3
for more information on LRE uplink logical ports.
shows the two twisted-pair, straight-through cable schematics.
Figure B-11
Appendix B Connectors and Cables
4 5 6 7 8
Figure B-2 shows the pinout.
shows the two twisted-pair, crossover
OL-6156-01