vagrant ports report in use after reload - vagrant

Question

I have a few vagrant VMs (both on Mac and windows, all running linux). I have port forwarding defined like this in the Vagrant file:
config.vm.network "forwarded_port", guest: 80, host: 9007
The first time I do a vagrant up it works fine. But then when I do a vagrant reload or vagrant halt followed by vagrant up I get this message:
Vagrant cannot forward the specified ports on this VM, since they
would collide with some other application that is already listening
on these ports. The forwarded port to 9007 is already in use
on the host machine.
To fix this, modify your current project's Vagrantfile to use another
port. Example, where '1234' would be replaced by a unique host port:
config.vm.network :forwarded_port, guest: 80, host: 1234
Sometimes, Vagrant will attempt to auto-correct this for you. In this
case, Vagrant was unable to. This is usually because the guest machine
is in a state which doesn't allow modifying port forwarding. You could
try 'vagrant reload' (equivalent of running a halt followed by an up)
so vagrant can attempt to auto-correct this upon booting. Be warned
that any unsaved work might be lost.
Then I have to change the port to bring up the VM, which is a pain. I have checked with netstat and lsof, and nothing seems to be using the port. I though it was perhaps a timing issue, and after a while I could use the port, but even after waiting many hours I still get the error.
This happens in both the Mac and Windows environments. Is there some setting that would allow me to reuse the ports?

Answer 1

I generally use static IP to avoid issues with port forwarding. Vagrant has an auto_correct feature to help fix that.
from vagrant forwarded port docs
It is common when running multiple Vagrant machines to unknowingly
create forwarded port definitions that collide with each other (two
separate Vagrant projects forwarded to port 8080, for example).
Vagrant includes built-in mechanism to detect this and correct it,
automatically.
Port collision detection is always done. Vagrant will not allow you to
define a forwarded port where the port on the host appears to be
accepting traffic or connections.
Port collision auto-correction must be manually enabled for each
forwarded port, since it is often surprising when it occurs and can
lead the Vagrant user to think that the port was not properly
forwarded. Enabling auto correct is easy:
Vagrant.configure("2") do |config|
config.vm.network "forwarded_port", guest: 80, host: 8080,
auto_correct: true
end
The final :auto_correct parameter set to true tells Vagrant to auto
correct any collisions. During a vagrant up or vagrant reload, Vagrant
will output information about any collisions detections and auto
corrections made, so you can take notice and act accordingly.