Chapter 1 Overview
Front-Panel Description
Note When connecting the switch to a 1000BASE-T device, be sure to use a four twisted-pair, Category 5 cable.
Note 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 port on the Catalyst 2940-8TT-S switch can be explicitly set to operate at full- or half-duplex at 10 or 100 Mbps. The port is restricted to full-duplex mode when it is set at 1000 Mbps.
The port 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 meters).
100BASE-FX Port
The 100BASE-FX port on the Catalyst 2940-8TF-S switch can use either 50/125- or 62.5/125-micron multimode fiber-optic cabling. The 100BASE-FX port operates only at 100 Mbps in full-duplex mode.
In full-duplex mode, the cable length from the 100BASE-FX port to an attached device cannot exceed 6562 feet (2 kilometers).
You can use only the 100BASE-FX port or the SFP module slot at one time. When the switch is first powered on, the 100BASE-FX port is enabled by default. However, if an SFP module is already installed in the switch, the SFP module slot is enabled.
You can connect the 100BASE-FX port to an SC port on a target device by using one of the MT-RJ fiber-optic patch cables listed in Table 1-2. Use the Cisco part numbers in Table 1-2to order the patch cables that you need.
Table 1-2 MT-RJ Patch Cables for 100BASE-FX Connections
Type | Cisco Part Number |
| |
1-meter, MT-RJ-to-SC multimode cable | CAB-MTRJ-SC-MM-1M= |
| |
3-meter, MT-RJ-to-SC multimode cable | CAB-MTRJ-SC-MM-3M= |
| |
5-meter, MT-RJ-to-SC multimode cable | CAB-MTRJ-SC-MM-5M= |
| |
SFP Module Slot
The SFP module slot supports copper or fiber-optic SFP modules. The SFP module slot is numbered as port 1.
Note You can use only the SFP module slot or the 100BASE-FX port at one time. When the switch is first powered on, the 100BASE-FX port is enabled by default. However, if an SFP module is already installed in the switch, the SFP module slot is enabled.
If you install an SFP module after the switch has powered on, you must reload the switch to enable the SFP module.
Catalyst 2940 Switch Hardware Installation Guide
