OK,

Looking into doing ipnat with only one ethernet card I _believe_ I found 
2 relevant documents, 1 that I understand completely ;) (at least the 
part that pertains to my cable modem), the other that perhaps one of the 
guru's out there could look over and tell me what's needed for me on 
NetBSD to do the same thing and get it working :)

Here are the URL's....They is not in any way related to NetBSD, but to 
Linux, but maybe they will give someone a starting point.

http://metalab.unc.edu/mdw/HOWTO/mini/Cable-Modem-3.html#ss3.6 (The one I 
understand)
     This merely explains that Jones Intercable uses the same Hybrid 
Cablemodem that RCN does
     and that the guy has IP masquerading working (ipmasq on Linux)

http://metalab.unc.edu/LDP/HOWTO/mini/IP-Masquerade.html#toc2 (the one I 
dunno crap about)
     This is the Linux IP Masquerading HOW-TO, dunno how useful it is, 
but it is perhaps a 
     starting point?

Thanks in advance for any help,

Greg