通过VPN连接到VNET的Azure Web App（网站）-VPN连接断开

Question

I have an Azure Web App (formerly web site) connected via VPN to an Azure VNet. It then connects over port 8080 to an Azure VM (running a RavenDB server) using the Azure VM's private IP (10.0.0.X). This has worked extremely well for me over the last 5 months.

This is the general method I'm using for connecting the Web App to the VNet: http://azure.microsoft.com/en-us/documentation/articles/web-sites-integrate-with-vnet/

This morning, my web app could not connect to the VM, throwing this error:

Unable to connect to the remote server 
at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar)
An attempt was made to access a socket in a way forbidden by its access permissions 10.0.0.10:8080 
at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult) 
at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)

Simply restarting the Web App fixed the problem. Is there some potential instability in the VPN connection? The problem seems isolated to the Web App infrastructure since a simple restart of the Web App solved the problem.

The potential problem here is that the VPN connection could go down or otherwise be impaired without any action being taken to repair the connection.

The workaround is to setup some kind of monitoring and reset the web app if this condition occurs, but it would be nice to hear the Azure team weigh in.

David

Answer 1

At this time, May 2015, there are still a few rare bumps that can happen with the feature. They are primarily caused when the VNET gateways are cycled which then may cause a problem with our client side of the VPN connection. We are working to provide a fix for this.