We have some strange things happening with a new installation of MSMQ on a Windows Server 2012 R2 Cluster:
- the clients reach the server without problems
- the server tries to send a message to the client and gets the error message "Failed to connect to winsock socket"
- the server is able to ping the client and vice versa
- restarting the MSMQ-Client on the clients (Windows 7 domain-members, same domain as the server) seems to fix the problem teporarily
- it only affects a few clients, and not always the same. We might have identified one of the reasons being that the network is not fully operational at the time the MQ-client starts. Starting the client without network connection always results in the error.
- the strangest thing: it only affect communication to the new 2012-server. The same clients have no problems communicating with MSMQ on 2008-servers, even when they can't communicate with the 2012 MQ at the same time.
One articel we found described opening the firewallports for RPC-EPMAP, which we did, unfortunatelly without helping. The log of the firewall shows no dropped packets.
At the moment we are clueless, especially since the Clients just work flawlessly with the Windows 2008 MSMQ-Servers.