Services for Unix "Network Error 53"

"Network Error 53", "The data area passed to a system call is too small" or "Unknown Error"

Client for NFS included with Windows Server 2003 R2 returns different errors when trying to access NFS shares on UNIX-based NFS servers. The exact error message may depend on your environment - you might get one or more from the ones mentioned above. And, at the same time, SFU 3.5 Client for NFS may work just fine.

Analyzing the network traffic may show MOUNT or NFS calls being "rejected for security reasons (5)".

The R2 Client for NFS uses high ports (>1024) to connect to NFS servers and that's known to cause the above errors. There are two ways to fix this -

Change how your NFS servers export the NFS shares and make them allow connections from high ports
OR
Add /UseReservedPorts /DWORD value under HKLM\Software\Microsoft\Client for NFS\CurrentVersion\Default and set it to 1.

Restart the Client for NFS service to allow the change to take effect.