On Mon, Nov 20, 2006 at 08:00:44AM +0000, hantslug@??? wrote:
> So the second IP can be entered in a ppp file and that provides the second 
> interface? And one needs two cables (one going to the internet/adsl and one 
> going to the private network?
Something like that, yes.
> Presumably, if instead of a modem, one has a single port "router", with an 
> RJ45 connection (which most people advocate with Linux rather than an adsl 
> modem), then one needs two interfaces - i.e. 2 cards - and two separate cat5 
> cables going to the 2 separate NICs/interfaces?
Yes.
> The "aboutdebian website says 
> 
> <quote>Adding A Second Network Card 
>  
>  Setting up a proxy or firewall system requires that the system have two NICs 
> so you would have to add a second network card to your existing networked 
> Debian system. If you want to use a Linux system as a router you would have a 
> system with multiple NICs, one for each of the subnets you wish to 
> interconnect.  </quote>
> 
> Is this in fact wrong?
It's not exactly wrong. You need two NICs (in practice). It's just
that one of those might be a PCI/USB ADSL modem rather than a regular
ethernet card.
> (Sorry - I was one of those involved in the debate and I was saying that I 
> could not understand how one network card could handle 2 IPs and 2 
> interfaces.  I'm afraid I still don't. :-(  Perhaps someone could show me at 
> the next BaB.)
It's possible to alias an interface so it responds to more than one
IP, but it's really not a good idea in this situation. Not worth
worrying about unless you want to get into virtualization or virtual
hosting.
-- Jamie Webb