[PLUG] Bridging two networks using linux

["Molnar, Bradley" <brmolnar@exchange.ursinus.edu>]

Here is my situation.

I am currently at my parents house.  They have a DSL line, but, they refuse
to run wires to the various rooms.  No big problem, they use wireless.

But, here is where my problem comes in.  The network uses an older Lucent
RG-1000 (basically a simple gateway).  I found an old laptop (P2 233) that
was running Stormix (which is now out of buisness).  But, the install was
bad, so, I put on the only thing I have cd's for -- redhat8 (the distro
doesn't matter except it is having troubles booting off the cdrom).

What I want to do with this is to use it to bridge from the desktop in my
room (wired) to the wireless to connect to the dsl and my parent's computer.
Yes, I know, overly complicated.

But, I don't want to use masquerading if at all possible.

I tried using the bridge software (addbr br0, addif br0 eth1, etc), but, all
that did was cause the network to go down on this laptop.  It has two PCMCIA
network cards in it, and both work and can connect to their respective
networks (when I don't have the bridge going).  Was there something big that
I missed on this one?

So, is there another, easy, way to do this.  I was thinking of using
iptables/ipchains to create a simple firewall that didn't block anything,
but, I couldn't figure out how to do this.  If this were done, would I set
the laptop as the router for the machines behind it?

I was also considering just making it it's own private network segment (the
current segment is 172.20. and I was going to use 192.168. for the other
section) and then adding a static route to my parent's machine (so that it
would know to go through 172.20.0.100 to get to 192.168. [as an example]).
But, I don't really know the best way to bridge these either.

To reduce (or perhaps add to) the confusion, I wanted to diagram this out a
bit.

DSL - Netgear Router - RG-1000 - Laptop A [the 233] - My Desktop
          |                  |
    Family Computer      Other Wireless Laptops

Thanks
-brad
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