[cumbria_lug] Windows Network Noise on the Net.

[Steve]

Schwuk wrote:
> On Mon, 2004-12-20 at 18:13 +0000, Ian Linwood wrote:
> 
>>I don't want to throw stones, but are you sure your LAN isn't letting
>>this kind of stuff out?
> 
> 
> Do you know something - I've never considered that before...
> 
> /me goes off to review my iptables setup!

Hmmmmm...  got me wondering there as well (yes I know what I said 
earlier that I'm not adding to the noise on the net)...  I know I'm not 
broadcasting netbios crap to the outside world from my router logs - not 
a peep of it in sight, yet I don't have any specific iptables for it 
(though I did!!!).

I think I'm right in thinking that netbios crap is only broadcast on the 
local subnet?  If so, then as my firewall/router is acting as gateway 
between two subnets and the stuff is only forwarded if and when I 
specifically address a machine on the other side, then I'm not actively 
sending it out anyway or need to actively block it (per-se).

Which I suppose means, that anyone using a router with a private IP 
range (192.168.x.x, 10.x.x.x, etc) NAT'd to the outside world won't have 
the annoying netbios traffic forwarded.

Using a dialup modem however would be a completely different matter, as 
the machine is on the net directly, and the local subnet *is* the 
internet!!!

Also, using a bridge to pass traffic would have a similar problem to a 
dial-up modem, as both sides of the bridge would be on the same subnet, 
so the netbios traffic would be forwarded.

I feel like I'm doing Networking 101 here...  have I got it about right 
though is the interesting question?