NetBIOS Over TCP/IP

We just endured agony from dealing with the team on the other side of the pond. Problem is relatively simple: the India team need to be able to access a shared folder serviced by a Bufallo NAS system, but we want to make sure that the port are opened on the corporate firewall.

First problem: someone changed the corporate WINS, and somehow the clients are not aware of this (even if it refreshes IP address). So \\MachineName is out, must use \\IPAddress instead, lucky that I setup the machine with static IP address.

Second problem: Since the Bufallo NAS is running Linux OS, the machine is offering shared folder service by talking SMB (old version). This poses a grave problem, it doesn't response on port 445, it only replies when someone talk to port 135-139. First the firewall administrator only open port 445 for TCP/UDP, this problem is solved quickly after mentioning Linux box and SMB.

Third and bigger problem: we didn't know the configuration of the PC on the other side. Normally the default advanced settings of TCP/IP looks like this:

But, the PC is setup with a disabled NetBIOS over TCP/IP. Dan found it through network sniffing and this link.