Check for VPN Connection Exists

Question

Hello
I am working on a windows store app for Enterprise. This app will require internet and VPN connection to get data. I have found a way to check for internet access. However, I am not sure how to check if there is a VPN tunnel available. If VPN is available
then I can make a call to a WebService and get data. If there is no VPN then the WebService call will fail [after about 10-15 seconds]. I can assume that if the WebService calls fails that means there is no VPN but there must be another way to find this out
before even calling a Service.
Please help.
Thanks
Bevan

Answer 1

We're using Microsoft Direct Access rather than a VPN but I think this is worth sharing anyway.
Rather than calling a web service I'm just using the HttpClient's GetAsync() method to call a small file hosted on an internally hosted web server. This minimises the payload as much as possible which may be important if your users are connected using devices
with 3G/4G with data limit.
I'm wrapping the call in a Stopwatch to get a rough idea of the round robin request/response and visualising that for the users so they know how good their connection to the corporate network is. This info is far more useful than the WiFi/Mobile signal bars.
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
HttpClient httpClient = new HttpClient();
HttpResponseMessage response = await httpClient.GetAsync(nslUri);
response.EnsureSuccessStatusCode(); // -- throw exception if not a success code
stopWatch.Stop();
TimeSpan ts = stopWatch.Elapsed;
This might also be of interest...
https://msdn.microsoft.com/en-us/library/windows/apps/xaml/windows.networking.vpn.aspx