dyn netbios/ip map

[michelegonella at libero.it]

Hi,
I need to write a daemon app to be run on a internet gateway
in order to set/unset iptables and traffic shaping rules based
on netbios names; after reading documentation and browsing
the the samba source code I am thinking of running just nmbd
on the gateway and from it to gather the informations needed.
The service should be designed to work in "almost any" windows
network architecture with mixed workgroups/domains and the
internal LAN could be subnetted.
What I want to ask is the easiest way of gathering a list of
netbios/ip_addr pairs relative to all the machines within the LAN
once smb.conf is set up correctly to map all the Domain Controllers
and Wins servers, plus of course what comes from broadcast registrations.
Actually I think I need something to poll with a settable refresh time.
Any ideas ? 
Will it be in any cases unreliable ?
If possible I wouldn't try to patch nmbd, because I want to update it
as soon as new releases are coming.

thanks in advance for any help or suggestions.

Michele