So, you've got your app server running on localhost port 1337, and you're running Sauce Connect so that our browsers can access it. This works just fine in Firefox and Chrome, but for some reason, Safari and IE utterly fail to load the site. Why the difference?
A little background on Sauce Connect: it runs a tunnel endpoint in our cloud, and one in the machine running Connect, such that requests made from our machines will appear to come from your computer. When Firefox and Chrome run in our cloud, the way they interact with this tunnel enables them to "see" your localhost machine as their own. That means that all ports are available to them.
By contrast, Safari and IE refuse to acknowledge your machine as "localhost". Their heads are stuck in the cloud. So, when they see a request for port 1337, they look for it in the Sauce VM.
To get around this, we run a process that grabs these requests and actively forwards them through the tunnel. However, this takes processing power, and we have to manually enable each port that is to be proxied in this way. So, not every port is covered.
Here's the list of proxied ports, which will work for any browser. We do our best to support those that are used by popular frameworks, such as port 3000 for Rails servers, so if you have a request, just let us know (via firstname.lastname@example.org).
you can either choose to run your server on one of those ports, or alternatively, direct your tests to a non-localhost URL.