Re: Bridged Network Question

[Douglas Allan Tutty <dtutty@porchlight.ca>]

On Thu, Aug 02, 2007 at 10:45:43PM -0400, Wayne Topa wrote:
> Douglas Allan Tutty(dtutty@porchlight.ca) is reported to have said:
> > On Thu, Aug 02, 2007 at 09:47:58PM -0400, Wayne Topa wrote:
> > > Douglas Allan Tutty(dtutty@porchlight.ca) is reported to have said:
> > > > On Thu, Aug 02, 2007 at 03:09:48PM -0400, Wayne Topa wrote:
> > > > > 
> > > > > I have been using an old laptop as an Access Point for our laptops to
> > > > > connect to the internet through the main box -> modem connection.
> > > > > The Lan (eth0) is bridged with a Netgear WG511U PCMCIA card (ath0) to
> > > > > connect to the gatway computer.
> > > > > 
> >  
> > I think I understand your setup, although I've never used wireless.  I
> > too am on dialup and at one point had a laptop that I connected with a
> > serial cable to a box that then connected to the box that had the modem.
> 
> The AP laptop -is- connected to the gatway machine via Cat5 cable to
> the gateway.

I understand that.

> 
> > 
> > I set up the access box with NAT at the time by simply installing ipmasq
> > and dnsmasq and setting forwarding.  All boxes could access the
> > internet.  
> > 
> > I never needed bridge and wonder why you're using it.  
> 
> Because I needed a way to connect the wireles laptops to the internet.
> The AP has the the wireless adapter and an ethernet adapter in it do
> does what you did with your laptop except it accepts wireless signals
> in/out.

> I'm about as happy with the bridge, as it is now, as I am with my
> 2.5KBs dialup connection.  ~6 minutes for each Meg downloaded is a
> bigger PITA but I don't have any other alternative, currently.  
> 

You don't need to bridge.  

If it were me trying to set this up, here's how I'd do it.  IP numbers
are examples only.

		Internet

		209.181.8.8
		    <=>			
		ppp0 
		Gateway box, masqurade using iptables
		eth0: 192.168.1.1
		    <=>
		eth0: 192.168.1.2
		AP laptop, masqurade using iptables.
		ath0: 192.168.2.1
		    <=>
		wireless0: dhcp e.g. 192.168.2.2
		user's laptop

A bridge gives all boxes the same network number but this isn't required
for your setup.  All your user's laptops would be on network
192.168.2.0, and their default gatway would be 192.168.2.1

The only things different from what I do all the time is the dhcp and
wireless (never used either).  The iptables setup I've always done with
either ipmasq (no config required) or for more control shorewall.

Good luck, I hope this helps.

Doug.