Webthority - Solving "No buffer space available" error on Windows Server machines
Unable to connect to the proxy host "No buffer space available"
Unable to connect to the proxy host either using a browser to access one of the proxy URLs or via remote desktop.
Proxy host had to be rebooted to restore service.
On Windows machines prior to Windows Server 2008 R2 / Windows 7, the default maximum number of ephemeral TCP ports is 5000.
A new parameter has been added in these products. To increase the maximum number of ephemeral ports, follow the steps described in Microsoft KB196271:
On Windows Werver 2008 R2 / Windows 7, the kernel leaks loopback sockets due to a race condition on machines with more than one core
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
Please refer to Microsoft KB2577795 (hotfix attached):