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UWP cannot connect to local Socket.IO server

I have an UWP application which is connecting to a Socket.IO server. When debugging I like it to be a local server, but I can't get it to connect it. I use the SocketIoClientDotNet library, and it works well if I have to connect to an external server, but I can't connect to the local one.
I'm aware that on default UWP apps forbids connecting to local servers, I think it's called loopback, but I'm also tried to go around that by using this tool:
http://loopback.codeplex.com/
However, It didn't helped.
Any help is much appreciated, and thanks in advance! : )

I think the problem is that you didn't enable the relevant capability in your project. Please open the manifest of your app can select the Capabilities label and check the Private Networks (Client & Server) on the left.
This capability's name is "privateNetworkClientServe", this capability provides inbound and outbound access to home and work networks through the firewall.
For more info about capabilities, you can refer to App capability declarations.
Update:
Due to loopback restrictions enforced by network isolation policy, when use TCP protocol, server and client must run on separate machines for them to be able to communicate with each other.

Connecting to SQL Azure database from client applications

I have a bunch of small desktop applications for which I have a simple database for keeping user data (who uses which app and in which version) etc.
I want the apps to connect to Azure SQL server and update database record when they're started. My apps have the ADO.NET connection string hardcoded in them.
It works fine from my home network and my company guest network - however, the corporate network has got some of the ports disabled, and that apparently includes port 1433. As per Microsoft troubleshooting guide, I tried telnet and failed.
C:\Users\xxx>telnet 65.55.74.144 1433
Connecting To 65.55.74.144...Could not open connection to the host, on port 143
: Connect failed
I cannot connect neither via my applications, nor by SQL Server explorer in Visual Studio.
So, the question is - how can I get around this problem? It is highly doubtful that corporate IT will unlock a port just because I ask, besides I want to keep it as simple, low profile and independent as possible. Or maybe my approach is incorrect from the very beginning and I should do stuff differently?
Cheers
Bartek

You can't.
Make your desktop applications talk to web services instead, over HTTP/HTTPS. Among other things this will also allow a more controlled access (right now anyone can connect to your database and modify the data, since your access credentials are publicly shared with your app).
A side effect of using we services is that 80/443 are almost always opened in all corp firewalls.

What blocks a .NET executable from creating a listening TCP port on localhost?

I have an application that creates a HTTP server on a random port (50000-59000) on "localhost". It tries to connect to this port afterwards to determine if everything was setup correctly and is ready to use.
This seems to work on most machines very well. Its written in C#.NET 4.0 for Windows XP and higher.
Now I have the problem that on one server at one customer the creation of the server seems to work but it can't connect to it. Sadly we didn't any information as the exception details were not outputted from this software as it has happened.
It works if the file is on local disk. If they start it from a specific Windows network share it stops working. I think that the have a special setting which causes this issue. But I don't know that could be reason.
My Question:
Do you know settings, an system administrator could make, that prevents a software, running as normal user, to connect to a listening port, that the program has opened just a moment ago? May be group policy settings in the active directory?
I've written a test program to try this again at our customer.

Request.Url.Host vs Request.Url.Authority

I've inherited an ASP.NET web application written in C#. In many pages throughout the site the hostname is retrieved using:
BaseHost = Request.Url.Host;
Since I am using Visual Studio 2012 Express and it's installed local IIS Express server, I seem to be stuck with a port number appended to the hostname (localhost) when I debug/run locally. The above code does not result in the port number being included and as such breaks links that are generated by code (menu item links, redirects, etc).
I see that I can overcome the issue by changing the code to:
BaseHost = Request.Url.Authority;
This seems to fix it by including the port when I'm running locally (localhost:4652) and when published to my staging server (development.mysite.com).
My question: Is this bad form? Is there a time or a situation in which this is going to cause problems on my live site? It just seems a lot easier to do a quick replace of all these instances. I've considered writing a small routine to append : with Request.Url.Port, but it seems easier just to use Request.Url.Authority. Too easy maybe...
I've tried to research my question online and at MSDN, but I don't see an answer.

According to MSDN Authority includes the port number while Host does not. Another aspect is that Authority will escape reserved characters if need be.
Without knowing your application it is hard to say whether it is a good idea, but in general I would suspect that it won't break anything... so go ahead...
Another option is to run the application IIS instead of IIS Express...

My problem with this is that it ALWAYS adds the port, even when the port is not required. This can cause issues with multiple servers in some cases For example, in a production server environment behind a firewall on a pair of load-balanced web servers, it kept putting the firewall port in place, but that caused the URL to break because the port was tied to a specific web server in the server farm that wouldn't map correctly through the firewall. So I would be very careful with this method if you're using it across multiple servers. It caused a breaking issue with our application and had to be reverted back to using Url.Host. Plus, it made production web URL's look weird with the port number.

Client/Server Application That Can Deploy Client From Server

I have a client-server application written in c#. I am hoping someone can give some direction on where to look in order to set it up where a user could connect to the server from their workstation, most likely through http but that's not a requirement, and download the client. The mechanism would need the following features:
Check for updates on client startup and automatically apply them.
Allow multiple clients (connected to different servers) to download on the same machine
Client can be downloaded by a non-local admin
Possibly install any prerequisites needed on the workstation
I currently use ClickOnce but it isn't quite working out. Currently the server sits in IIS and uses WCF services.