Remote MSMQ access issues when working with QueueExplorer

QueueExplorer uses MSMQ API calls for all its MSMQ operations. Therefore it communicates with local MSMQ server, which in turn then communicates with remote MSMQ.

What to do when you get security related error?

  • Make sure that MSMQ is installed and running on local machine even if you only need remote queues.
  • MSMQ uses RPC and sometimes when working first time on remote machine RPC doesn't yet have authentication details. You can use Windows "Credential manager" to manually set username/password used for accessing remote machine. These credentials are used for MSMQ as well. Alternatively, try to open some shared folder on that remote computer over network, that would also bring up username/password dialog if you didn't connect there before.
  • If you need some other credentials than current user, you can run QueueExplorer using "Run as".
  • Problem could be also on remote machine. Check MSMQ security there. You can't do that from QueueExplorer, you'll have to log on remote server and use Computer Management to do it. Each queue has its own security settings.
  • If MSMQ is installed in "Active Directory" mode, there's also Security tab for entire MSMQ, not just for individual queues.
  • It's not enough to grant access to "Everyone" group since it covers only accounts recognized by the domain. You can also grant access to "Anonymous" or "Guest" accounts.

Things that could be turned off during troubleshooting

Here are some settings that you can turn off while troubleshooting MSMQ access issues. It should be switched back on once it's working.

  • Under Computer Management / Message Queuing, right click / Properties, you can uncheck "Disable un-authenticated RPC calls". It applies to workgroup mode too. "Hardened mode" and "Secure mode receiving" could also be turned off.
  • Temporarily turn off Windows firewall on remote server, or at least check if Message Queueing inbound and outbound rules are enabled.

More articles for further troubleshooting:

"How To Configure a Firewall for MSMQ Access"
http://support.microsoft.com/kb/183293

"TCP ports, UDP ports, and RPC ports that are used by Message Queuing"
http://support.microsoft.com/kb/178517

Additional details are available in this blog post:
http://blogs.msdn.com/b/johnbreakwell/archive/2008/04/29/clear-the-way-msmq-coming-through.aspx