I have a new building to add to our campus and I have been encouraged to run single mode fiber. All of my other buildings are connected with multi-mode fiber. I just want to make sure i will not have an issue if I run single mode to the new building with SM SFP's.
each port is a different matter regarding the physical layer you can have different ports using SM and MM fibers on the same device with no issues.
A single port can use SM EXOR MM fiber depending on the installed SFP
Hope to help