IIS Express reports all ports already in use

Question

When I try to run IIS Express by debugging an asp.net application in visual studio, I get an error message that the port is being used by another application, regardless of which port I select in the project properties under "Web". Why?

Answer 1

Fount the same issue, changing any port was getting the same error but...

after running in a elevated CMD:

netsh http add iplisten ipaddress=::

and then

netsh interface ipv4 show excludedportrange protocol=tcp

Saw some ports being managed in the range I was "randomly selecting"

After changing to a range that was not in the managed ports, I was able to debug again.