Wikipedia mentions only TCP port 445 (while as far as I can remember ports 137-139 used to be used actively by Windows file sharing).
If I map the 445th TCP port on gateway host "A" to a 445th TCP port of SAMBA server host "B", will Windows XP client host "C" be able to access shared folders on "B" by typing "\ipAddresOfHostA\" in his address bar while being connected with "A" with OpenVPN TCP/IP tunnelling?
PS: No broadcasting and discovery features needed – clients will always explicitly specify UNC address to access the resource.
Best Answer
Your memory of ports 137 and 139 relate to NetBIOS over TCP/IP. SMB directly over TCP uses port 445.
Allowing TCP port 445 from a Windows XP client to a Samba or Windows Server computer will permit the client to "map" a "drive" to SMB shares exported by the server computer so long as you use the IP address of the server computer in such a request. Just to be sure, I verified with Windows XP Professional 32-bit SP3 against Windows Server 2003 R2 SP2 and Samba 3.0.33 running on CentOS 5.5, through a packet filter that allowed only TCP port 445 traffic from the client to the server. I was able to "map" "drives" and access files on the remote machines.