[ale] What do I need to bridge two networks?

[Alex Carver]

On 2/4/2014 06:59, Jim Lynch wrote:
> On 02/03/2014 05:33 PM, Brian Mathis wrote:
>> This brings up the question of why do you need to provide a wireless
>> access point to your clients, only to bridge it to the other wireless
>> network?  All the airwaves are the same, so why not go directly to the
>> main WiFi AP?  If there's something preventing you from doing this,
>> there's likely a reason and you should be working with those in
>> control to get the access you need directly on the existing wireless.
> OK, the space we are in is donated.  Their generosity is limited. Two
> reasons I don't want to go to the "public" rf space is security and I
> need to know what IP address the devices have received and the easiest
> way is to look at the router DHCP tables. I can't do that on the public
> router.  I suppose I could use nmap.  Also some of the devices are too
> far from the router. The guy controlling the network works for a company
> that is renting space in the same building.  The guy that is donating
> the space owns the building.  From what I can gather the network admin
> isn't happy about letting us on "his" network and the building owner
> doesn't want to upset a paying customer.      We don't have a lot of
> negotiating leverage here. The operation is on a shoestring as is so
> there is no money to get our own line put in.

Do any of the machines need to be accessible from the outside?  Because
it sounds like the solution is a wireless device in STAtion mode
(client) to connect to the remote router, then use your own wireless
router as the AP and network manager for the rest of your wired and
wireless devices.  An Rpi or other small device running NAT would work
just fine in this configuration and you wouldn't suffer the performance
penalty of using WDS (Wireless Distribution System) especially if your
one device doubles up as the STA and AP simultaneously.

I did this very thing at work for a temporary setup until I could get a
line pulled from the closet.  I had a Meraki mini running OpenWRT.  I
used its wireless interface in STA mode to connect to the building
wireless and then plugged its ethernet port into the WAN port of a
regular Linksys WRT54G running stock firmware.  It was a double NAT
setup since the Linksys was also running as a NAT device but it worked
fine, I could perform system updates, browse the web, and I even had
some port forwards set up so I could remotely access a couple of the
machines.  From the building's perspective there was only one machine
(as is the way of NAT).

You could easily replicate this setup with an Rpi, Beaglebone, another
Linksys WRT or any number of other devices.