Cisco Catalyst 3750-X and 3560-X 4-Port 1G SFP Network Module

Cisco lists the C3KX-NM-1G as the 1 Gigabit Ethernet network module for the Catalyst 3750-X and 3560-X. It has four 1-Gigabit SFP module slots. Standard 1 Gigabit SFPs work, including copper (GLC-T), multimode and single-mode fiber (SX, LX/LH, ZX, BX), CWDM and DWDM types. SFP+ modules do not work in this module: if one is inserted it stays non-functional and the switch logs an error.

Two restrictions apply. GLC-T is not supported for NEBS, and GLC-GE-100FX is not supported in SFP+ slots. The module is hot-swappable, and Cisco recommends installing it before powering the switch and before any SFPs are fitted. A number-2 Phillips screwdriver tightens the captive screws.

Each port has an LED: green is link up with no activity, blinking green is activity, blinking amber is a fault or configured limit, and amber is a disabled SFP link. An interface can become error-disabled when a module with connected fiber is installed or removed, and shutdown followed by no shutdown re-enables it.

The sibling modules are the C3KX-NM-10G, which has four slots where two take only 1 Gigabit SFPs and two take either 1 Gigabit SFPs or one 10 Gigabit SFP+ module per slot pair, and the C3KX-NM_BLNK blank module, which has no ports. Cisco says the switch meets EMC, safety and thermal specifications only with a network module installed.

See the Cisco switches category and the C3KX-PWR-350WAC power supply for the same switch family.