LinuxPlanet: Routing NetBIOS with Linux

“The Microsoft Network Neighborhood relies on an underlying
technology called “NetBIOS over TCP/IP” to work. This all works
fine on a small LAN, as it relies on network broadcasts, but it can
fail over a WAN as many routers cannot forward NetBIOS broadcasts,
or they may be performing Network Address Translation which may
cause the broadcasts to fail as they contain IP addresses–not only
in the header, but in the data.”

“If you can access a machine on a different, masqueraded network
using UNC naming, e.g. \server, but you cannot see it or any
machines in your Network Neighborhood, then chances are the NetBIOS
broadcasts necessary for Network Neighborhood to work are not
crossing the networks.”

It’s possible to configure a Linux machine to do NetBIOS
forwarding, which will enable us to get the Network Neighborhood
working across masqueraded networks. Here’s how…