Question : Seperate wireless and wired networks, but share single DSL

I need recommendation on sharing a single DSL router with an existing wired network and a future wireless network.  But, the wireless network must not access any computers on the wired network (and vice-versa).  I found a product by D-Link called a "Hotspot Gateway" model DSA-3100 which appears to be a solution, but was wondering if a managed switch could do this or be better at doing this.  Unfortunately, I have no experience with managed switches.  LinkSys has no such product and thought one of their managed switches would do the trick but weren't real sure.  Was hoping someone had DSA-3100 experience (D-link puts me on perpetual hold, and LinkSys gives me a foreign person I can't understand).

Answer : Seperate wireless and wired networks, but share single DSL

What you are looking for is a kind of functionality which is referred to, in commercial network switching, as a "VLAN".  It's effectively the same thing as splitting your switch up into multiple switches, so that layer two broadcasts do not cross from one set of interfaces, on the switch, to another - traffic passing between VLANs must pass through a router interface, if they are to reach one another, at all.  (Some switches also have routing modules, which will perform this function, as well, at the high-end of commercial switches.)

You can probably pick up a used Cisco 1900-series switch, capable of running VLANs, on eBay, for around $100, but you'll still need to add a wireless access point, and possibly a router, to the mix, somehow, depending upon how the rest of your network is set up.

If I had to make a reccommendation for a small office environment, I'd suggest that it's worth a few extra bucks to get an old Cisco, over a new Linksys or 3Com or Dlink, in the managed switch world.  It's a whole lot easier to find staff who know how to run a Cisco, than any of the other brands, and there is a wealth of software, print media, and online support forums for the Cisco products - where the others force you to rely on limited-availability tech support staff, who are likely to be 'multilingual' (which, in the US these days, means that they speak some other language than English - and do not necessarily speak English well enough to do so on the telephone...  :-/)

Remember, too, that the router is probably going to need to understand VLANs.  To do this well, you might either get yourself an old Cisco 2514 (two ethernet interface router, available on eBay for around $150) or perhaps a new Cisco DSL router/modem (not sure how much they cost, but I'm thinking around $250).  It's best that your router and switch both come from the same vendor, since some of the VLAN protocols are vendor-specific.  Some are interoperable, but it's not worth fighting that battle...  :)

Hope that helps...  :)