Insufficient Winsock Resources Available to Complete Socket Connection Initiation

Seemingly out of the blue, one of our customers could no longer log in to their CRM. As it appeared to be an authentication issue, I began troubleshooting on their ADFS server. Upon opening the ADFS Management Console, I was greeted with the following error message:

In the event viewer were a number of errors similar to this:

Microsoft.IdentityServer.Configuration.ReadServiceConfigFailedException: MSIS2001: Configuration service URL is not configured. ---> System.InsufficientMemoryException: Insufficient winsock resources available to complete socket connection initiation. ---> System.Net.Sockets.SocketException: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full 127.0.0.1:1500

Well, this was a new one for me but at least the error message actually gave a description instead of something generic. Logic dictates that if there isn’t enough of something, give it more. In this case, it appeared to me that ADFS was complaining about not having enough ephemeral ports so I figured I would increase the number available.

1. Start Registry Editor.
2. Locate the following subkey in the registry, and then click Parameters:  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
3. On the Edit menu, click New, and then add the following registry entry:
   Value Type: DWORD
   Value Name: MaxUserPort
   Value Data: 65534 (decimal)
4. Reboot server

After completing the above, ADFS was able to open the connection to its database and users were able to log back in to CRM. Now, it may be worthwhile to investigate exactly why ports suddenly became busy… perhaps there is a socket leak or new applications were installed… but this should at least get you up and running in the meantime.