Gulp + BrowserSync + Osx + Mamp, external devices not connecting

OSX: v10.11.6

Node: 6.10.3

Npm: v3.10.10

BS: v2.18.8

Mamp: v3.1

Trying to get BrowserSync working with gulp on my local machine so I can test a site hosted in Mamp across multiple devices.

BrowserSync on the local machine is working fine (it's refreshing when I change a file and I can view the UI on port 3001), however I cannot get any external devices to work at all... In Safari on my iPad Mini it's saying:

"Safari cannot open the page because it count not connect to the server."

Some of the things I have tried/tested include:

1. All devices are connected to the same wireless connection

2. Tried to good old classic "reboot" of the router, local machine and devices

3. Have tried turning off the firewall in Preferences -> Security & Privacy on the local machine

Current BS code looks like this (although I have tried so many different things over the last 1.5 days):

browserSync.init({
     proxy: 'http://www.localdownundr.com/',
     open: 'external'
})

Outputting into Terminal:

 --------------------------------------
       Local: http://localhost:3000
    External: http://192.168.8.103:3000
 --------------------------------------
          UI: http://localhost:3001
 UI External: http://192.168.8.103:3001
 --------------------------------------

Where "http://www.localdownundr.com/" is the local server name as defined in my Mamp etc file:

<VirtualHost *:80>
    DocumentRoot "/Users/timbo/Desktop/Websites/www.localdownundr.com"
    ServerName www.localdownundr.com
    <Directory "/Users/timbo/Desktop/Websites/www.localdownundr.com">
        AllowOverride All
        Order Allow,Deny
        Allow from all
    </Directory>
</VirtualHost>

Please, any help to get external devices connected would be greatly appreciated!

via Tim Blackburn