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I feel this is SF worthy (as opposed to SU) as I go into a bit of detail on gateways/routing.

Here's my ideal setup (if possible) -- there is a wifi network (lets call it bob's) with which I want access to, but I have a few other wifi-connected computers on my network which I want to keep behind a firewall.

So I was thinking of buying a wireless access point so that I could set it up to connect to bob's network from the AP, and then from my server, connect to the AP via ethernet. So that's the first bit. Second part is that I want to have my own private wifi network off the back of this; can I then tell the AP to serve a new network called foobar.

When I say private network, I mean that my server is actually a Debian linux install with routing configured (and I also do some QoS stuff on, etc). So ideally, I'd like all the clients on the private network to be behind the server in terms of routing. However, if the private clients connect to the server via wifi, then aren't they exposed to the "public" network? That is, if someone is savvy enough to scan for my IP range.

Also, to do routing I'd need to connect two ethernet cables between the server and the AP (because you can't do routing/QoS on virtual devices) -- which isn't a problem really; but I'm not sure whether the AP will allow me to separate the public and private LANs.

Or, as well as the AP, am I better getting a wifi-to-ethernet adapter for the server? I could use a wifi usb, but this can be tricky to set up on headless linux; plus the signal strength is a bit lousy. I cannot use a PCI card because the server is a micro ATX Atom PC.

If this question is a bit vague/spurious in places, please comment and I will explain in more detail.

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up vote 2 down vote accepted

Yes there is some wireless hardware can do this. If your AP only has one radio it will likely cost you in performance. APs with multiple radios tend to support setting up multiple SSIds. With the right hardware something like dd-wrt can be used to accomplish this pretty easily.

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Thanks - great answer. Off the top of your head, could you humour me with names of readily available hardware? I need something I can get quickly, which will definitely work. Also, does dd-wrt have a way of separating networks physically, so to speak? – nbolton Mar 25 '10 at 20:13
I have direct experience with a linksys wrt54gl. While wrt54gl did work it wasn't particularly reliable at home. I never figured out if it was my hardware in particular or dd-wrt that was the cause of the problems. I don't have any options or experience with anything that supports N. DD-WRT does support setting up vlans on the ethernet interfaces. So each port can be on a separate vlan. – Zoredache Mar 25 '10 at 20:18
The DD-WRT site has a whole list of supported hardware. Beware though - this is not a trivial undertaking! – uSlackr Mar 25 '10 at 21:27
A cheaper alternative to linksys hardware would be buffalo ones - WHR-G125 or similar would do you fine. Check with the dd-wrt site for compatibility charts. – sybreon Mar 26 '10 at 0:37

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