Dual-Speed Stackable Hubs User’s Guide
Fast Ethernet Module (DFE-260TX)
A Fast Ethernet module provides one additional twisted-pair Fast Ethernet connection. A twisted-pair connection of this kind is particularly useful for creating a link between two DFE-916 series hub stacks, placing them in separate collision domains. A link of this sort eliminates the need for a separate switch to separate stacks into separate domains. Separating the stacks into separate collision domains overcomes the Fast Ethernet two- repeater limitation, and effectively doubles overall bandwidth.
The recommended use for this module is to connect to another module of this kind in a second stack.
The Fast Ethernet module uses a MDI-X connector (not a straight MDI-II); therefore, a crossover cable must be used when connecting the module to another module (and under most other circumstances). See Appendix A for pinout information.
The Fast Ethernet module includes the following LED indicators:
∙Power/Tx—This LED is lit when the hub is on, and blinks when pack- ets are being transmitted by the module.
∙Link/Rx—This LED is lit when the port is properly connected to a powered-on device, and blinks when packets are being received by the module.
