Hello,

I have the problem that since 2015.01.28 ~22:00, my service deployed as a workerrole in an Azure instance cannot reach 3rd party webservices. This was a sudden issue as it worked for half a year without any changes.

The 3rd party webservices work fine, I can reach them from my development environment without any trouble, the provider of these webservices also could assure me that it works fine for others.

The call that fails is a simple WebClient call (with credentials) to a URL in order to read a (tiny) file and take followup actions.

The call fails with the following error:

System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond <ip:port>

The question: have there been any changes recently, either in the Azure services environment or networking that could explain this?

If i connect remotely to the instance and attempt to make the calls manually via IE, they succeed, but very slowly.

I have deployed the service to another datacenter as a test, so right now I have one running in East US and Western Europe, but both face the same issues. The service is running on Azure SDK 2.1, the instance is running on windows server 2012R2.

The service works fine when I run it on my development environment via compute emulator. No connection issues.

Any help is welcome, thanks ahead.

Looks like a timeout issue. Try to increase timeout of your call to see if you get any success. If OK, then for sure it is timeout problem. Then check if it is DNS problem. Use IP address to call instead of hostname. You mention it is slow in IE. Where is IE located? You can also try to call using IP address instead of hostname to see if it speeds up. Is it slow only the first call?

In the end it turned out that the 3rd party site was blocking the shared external IP of the Azure VMs.

• Marked as answer by RH_CT 2 hours 34 minutes ago