
SFC is the system file checker, used to check a Windows OS install’s files for any corruption and to replace them with legit working files. DISM (if I remember right) is a tool for turning a Windows install into install media, and has some similar features for ensuring the installed OS has no corrupted file issues.
So pretty much the option to “Verify Integrity of Game Files” for Steam Games, but for the OS. And also by Microsoft, so of questionable usefulness/functionality.
I spent almost 5 years in the trenches of tech support in a Windows environment. I still used those commands as a hail mary when I didn’t have any other ideas and needed some extra time to research. I think I’ve only seen it actually help three times.
There are mitigations possible against allowing unrecognized MAC addresses from getting network connection when plugged into an open port.
Security is meant to have layers. Defense in depth.