Team Foundation Server: An existing connection was forcibly closed by the remote host

iis-7team-foundation-serverwindows-server-2008

I've been trying to get my TFS (2010) environment to play nice for the last couple days but have been getting this error after using the TFS server a little while:

The Underlying connection was closed: An unexpected error occurred on a receive. / An existing connection was forcibly closed by the remote host.

I can't figure out why the TFS server will work flawlessly for a while, and then on a whim just decide to kick this out everywhere.

From Dynamics AX 2012 Developer Environment:
From within Microsoft Dynamics AX Developer Environment

From Visual Studio 2010:
From within Visual Studio 2010

However here's the confusing part, neither the TFS Server or the Client computer have any errors/warnings in the Event Log. Additionally, the Web Portal can be accessed for the TFS Server:

Web Portal

Google searches don't really bring up much useful information. I found this article which prettymuch describes a similar problem, but I'm not using an ISA Server, so the solution isn't valid.

The majority of the remaining results involve a similar but different error with SSL Self-Signed Certs. The error is happening on a non-ssl port, and our SSL port (8081) has a proper Authority Signed SSL Certificate.

I'm running out of ideas, I need to be able to get my TFS consistent. The installation was smooth and simple, no bumps, just a little hurdle to get it to use a FQDN but after that was done the TFS server was usable, creating Team Projects / Etc.. No issues until it decides to kill all inbound connections with no reason/warning/log.

Here's a snapshot of my TFS Settings:
TFS Settings

Does anyone know where I can look for more information, what might be happening or what I might be doing wrong here?

Best Answer

Hopefully you resolved this already, and you can share what was wrong. As you noticed, this likely relates to a network or DNS issue. I assume this is occuring from more than 1 computer. Regardless, I hope the following tips help you and other users with such issues.

If not resolved yet, the first thing I would do is run the TFS Best Practices Analyzer (BPA); this is part of the TFS Power Tools (December 2011 release).

You might also try using Fiddler to look at what the requests and responses are coming from the server. Here is a post that is a little older that has some tips to lead you in the right direction about doing this Could be:

  • A firewall or DNS issue To test, try turning off firewall on the client and server machine, sometimes the anti-virus programs also shut off ports depending on the tools you are using. Also, try connecting using the IP address instead of the DNS address.
  • Proxy settings in your internet settings (Internet Explorer) To test, check the behavior of the proxy or disable it on the client machine.
  • A virus Run a decent anti-virus.
  • A bad entry in your HOSTS file Look over the HOSTS file on the client machine.
  • DNS settings in your network settings Check the TCP/IPv4 Advanced Settings, especially the DNS tab.
  • A corrupted cached TFS connection *You can clear connection from the cache using TFPT connections on the command line using the TFS Power Tools*