How to debug “Vagrant cannot forward the specified ports on this VM” message

Question

I\'m trying to start a Vagrant instance and getting the following message:

Vagrant cannot forward the specified ports on this VM, since they
would collide wi         


        

Answer 1

As message says, the port collides with the host box. I would simply change the port to some other value on the host machine. So if I am getting error for

config.vm.forward_port 80, 1234

then I would change it to

config.vm.forward_port 80, 5656

As 1234 might be used on my host machine.

For actually inspecting ports on any machine, I use the tcpview utility for that OS and get to know which port is used where.