First my assumptions (possibly wrong):
- 100BASE-FX -> Multi-mode fiber
- 100BASE-LX -> Single-mode fiber
In fact, if I check some online information from CISCO regarding SFPs, it confirms my assumptions: https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/fast-ethernet-sfp-modules/product_data_sheet0900aecd801f931c.html
But the situation is that I found some products on the web that are designed for single-mode fiber but they use the 100BASE-FX designation. Is this wrong? Is any 100BASE-FX SFP capable of communicating trough both multi-mode and single-mode fibers? If not, how can I know that a 100BASE-FX SFP will work with multi-mode or single-mode if it is not clearly stated?