vagrant port forwarding guest and host port messed up - vagrant

Question

I'm using a vagrant trusty64 box with nginx, flask, gunicorn and port forwarding is not working as expected
In the vagrant file, I have:
config.vm.network "forwarded_port", guest: 8090, host: 3100
config.vm.network "private_network", ip: "10.10.1.10"
On the box, I have run:
gunicorn myprj:app -b 10.10.1.10:8090
find nothing on host machine with http://10.10.1.10:3100
trying curl -v http://10.10.1.10:3100 gives the following output:
connect to 10.10.1.10 port 3100 failed: Connection refused
Reachable with guest port on host machine http://10.10.1.10:8090
I am new to the vagrant, did I miss/mess to Vagrant file.
Complete Vagrant file:
Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/trusty64"
config.vm.box_check_update = false
config.vm.network "forwarded_port", guest: 8090, host: 3100
config.vm.network "private_network", ip: "10.10.1.10"
config.vm.synced_folder ".", "/vagrant_data"
config.vm.provider "virtualbox" do |vb|
vb.memory = "1024"
vb.name = "lopamudra_dev"
end
config.vm.provision "shell", inline: <<-SHELL
# Upgrading the environment
apt-get update
apt-get upgrade
# Installing nginx + uwsgi + flask
apt-get install -y python-pip python-dev nginx
pip install uwsgi flask gunicorn
SHELL
end

Answer 1

You are forwarding container 8090 to hostIP:3100 (localhost:3100)
At the same time you are creating a IP to access your container with 10.10.1.10 and you container has 8090 exposed, thats why you can acces it on 10.10.1.10:8090
# Create a forwarded port mapping which allows access to a specific port
# within the machine from a port on the host machine. In the example below,
# accessing "localhost:8080" will access port 80 on the guest machine.
# NOTE: This will enable public access to the opened port
config.vm.network "forwarded_port", guest: 8090, host: 3100
# Create a private network, which allows host-only access to the machine
# using a specific IP.
config.vm.network "private_network", ip: "10.10.1.10"