OSX-XP filesharing over the Internet

Dr. Lapin

We have a LAN consisting mostly of Mac OS X systems with a few XP systems. The XP systems on the LAN have no trouble connecting to our OSX file server. The LAN is behind a firewall, but port 548 is open so staffers can work from home and fileshare with the fileserver.

Port 445 is also open on the firewall so XPs can fileshare over the Internet (i.e. so staffers can work from home) -- except they can't. XP always tells us it can't find the address.

Of course the XP systems on the LAN are connecting to an internal address (192.168.x.x) and the XP systems outside are connecting to a static ip address on the Internet. These same XP systems can ping the file server and can find port 80 open at the ipaddress, but can't find port 445 for filesharing. Macs can find 548 and 80 at this address.

In fact, when we take down our firewall completely (for a few seconds, for diagnostic purposes only), the XP systems still can't find the file server, so presumably the problem is not how I've set up the firewall.

Or perhaps we're going about this the wrong way?

Any help is appreciated.


I think you need to configure your routers to send SMB file sharing traffic to your internal 192.168.x.x machine.

IMHO exposing a WinDoze machine to internet SMB traffic is an incredibally dangerous thing to do. File Sharing is one of Windows's weakest links and is one of the main ways that virsues, spyware and the like break into your machines.

Samba (SMB) on the Mac has fewer issues, but it too could cause some problems for the LAN-based Windows machines that connect to it. This is because they could copy over a virus that the Mac itself is immue to.