10/100/1000 Ports - Cisco WS-C2950-12 Hardware Installation Manual

Chapter 1 Overview

10/100/1000 Ports

Note
Note
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When set for autonegotiation, a port senses the speed and duplex settings of the
attached device and advertises its own capabilities. If the attached device supports
autonegotiation, the port negotiates the best connection (that is, the fastest line
speed that both devices support and full-duplex transmission, if the attached
device supports it) and configures itself accordingly.
The 10/100/1000 ports on the Catalyst 2950T-24 switches use RJ-45 connectors
and twisted-pair cabling. The ports can connect to these devices:
10BASE-T devices, such as workstations and hubs, through standard RJ-45
•
connectors and two or four twisted-pair, Category 5 cabling.
100BASE-TX devices, such as high-speed workstations, servers, hubs,
•
routers, and other switches, through standard RJ-45 connectors and two or
four twisted-pair, Category 5 cabling.
1000BASE-T devices, such as high-speed workstations, servers, hubs,
•
routers, and other switches, through standard RJ-45 connectors and four
twisted-pair, Category 5 cabling.
When connecting the switch to a 1000BASE-T device, be sure to use a four
twisted-pair, Category 5 cable.
When connecting the switch to workstations, servers, and routers, be sure to use
a twisted-pair straight-through cable. When connecting the switch to hubs or other
switches, use a twisted-pair crossover cable. Pinouts for the cables are described
in Appendix B, "Connectors and Cables."
The 10/100/1000 ports on the Catalyst 2950T-24 switches can be explicitly set to
operate at 10, 100, or 1000 Mbps but only in full-duplex mode. They can also be
set for speed autonegotiation, compliant with IEEE 802.3AB. In all cases, the
cable length from a switch to an attached device cannot exceed 328 feet
(100 meter).
Catalyst 2950 Desktop Switch Hardware Installation Guide
Front-Panel Description
1-7