Re: [vox-tech] 2-nics question
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Re: [vox-tech] 2-nics question
Dave Margolis said:
> I want to put an ancient laptop to use as a wireless bridge. My Gamecube
> sits in a room that I can't get ethernet to without a lot of effort.
> I could buy the Linksys _gaming adapter_ or any of several similar
> but I figured this would be worthwhile experiment and I can save some
I do not know about the gamecube side of things, but if I replace gamecube
with "generic computer" then what you describe is possible.
This may be useful as a resource. http://nocat.net/ This is a group of
people who have been working on making wireless access points out of
cheap/slow hardware. Their purpose is for creating a community-services
and sourced Internet access for others. However, their project can also be
used to helpyou with the filtering/NAT and other parts.
They have also had discussion on their lists for creating wireless routers
(wireless to wireless kinds of "range extenders" for network access.
> Here is what I have:
> P-I 100 / 40MB ram / 2GB HD - Toshiba Laptop
> Slackware 9.1 slim install < 200MB for base install and some networking
That can be a NAT/DHCP box easily enough.
> 1 wired pcmica nic (dhcp server to the gamecube, and perhaps other
> devices if I get a hub or switch) - eth1
> 1 wireless pcmcia nic (dhcp client to my wireless router) - eth0
> I just installed the OS and everything is working. The wireless nic is
> talking to the router and the outside world. I configured the wired card
> as 192.168.1.1 (my _normal_ home network is 192.168.0.0).
> Here is where I don't know what to do next. I've got DHCP installed, but
> I've never configured it before. Assuming I can get DHCP working through
> that nic, what software do I need or what configuration is required to
> _pass_ the internet through this machine. I know I'm showing my
> networking ignorance here, but I've always used a hardware router...
This is not clear. If the laptop will be a dhcp server, then you can check
out the free dhcp server from ISC. You configure it to server addresses in
a subnet. (In this case, the subnet to serve would be 192.168.1.0/24)
It is possible to have a single dhcp server on a network and use DHCHP
relay across subnets, but that will raise the bar on education
requirements when compared to a new dhcp server.
Next, you will need to setup some kind of NAT or masquerading of IP
address information. I expect this will be necessary as your commercial
NAT/Masquerading/Router/Wireless unit is probably configured to only NAT
for the private network for which it is subnetted.
Depending upon the NAT/Masquerading/Router/Wireless unit, you may be able
to have the laptop just act a a router (without NAT/Masquerading) but this
will require support on the NAT/Masquerading/Router/Wireless unit for
routing so that it will know where to "route" packets for the new subnet
based on destination address.
One advantage to simple Masquerading/NAT is that it is modular; you only
need to configure the box doing the NAT and do not need support from the
gateway that is used by the box being configured.
> For this part, I'm sure I can
> RTFM, but if anybody can give me a quick 1,2,3 or point me in the
> of good reading material, that would be great.
There are NAT/Masquerading how to on the linux documentation project site.
These cover setting up NAT/Masq as well as DHCP server setup. These HOWTO
are "the quick 1, 2, 3." Certainly it is possible to have a shorter list
of steps customized on a per user, per requirement case, but such
documents have little use for the general population. The HowTo are good
generic docs which cover most generic tasks people desire to accomplish.
> The part I'm really unclear on is this: do I need a crossover cable to
> talk to the Gamecube (or whatever dhcp client)? If I plug a hub into the
> wired nic, does that require a crossover cable, or a regular one?
Some newer NIC can auto-sense and auto-flip to match the devices to which
they are connected. (If the device is a hub, then connection is "normal"
while connections directly to other devices can cause the NIC to switch Rx
and Tx to also have that work.)
> I haven't bought the gamecube network adapter yet, and I wasn't planning
> on doing so until I proved this would work (I can always test with another
I do not know about the gamecube side of things, but I know what you
describe is possible for other devices. I have setup my laptop as a
wireless to wired-network router back when wireless was new and some
people wanted network access shared.
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