Let's Get into It
Updated 11/13/02 First, the WET11 is not a repackaged WAP11 Access Point, but is based on the Ubicom IP2022 Internet Processor. Earlier information from Linksys indicated that the WET used a technique called Multi-Protocol Label Switching (MPLS), instead of more conventional bridging code, but this turned out not to be true.
Whatever technique used, the WET's black-box magic should be invisible to the average user, who would see only the end result, i.e. the ability to have not just one, but up to 30 clients behind each WET11 connected wirelessly in the same subnet without any muss or fuss, and with the ability to share printers and files intact.
One key point about the WET11 that bears special emphasis is that it cannot be set to function as a standard Access Point, i.e. support wireless clients that are operating in Infrastructure mode. When you set the WET to Infrastructure mode, that means that it will look for an Access Point (or wireless router) to connect to, but not allow clients set to Infrastructure mode to connect to it. The difference may be difficult for wireless networking novices to understand (heck, I had to think about it for awhile before I got it!). So I'll be doing a companion article shortly that will explain how to use the WET11 in various network configurations, so you can get a better idea of what it can do (and how to do it).
In my testing, I was able to use two WETs in AdHoc mode to create a wireless bridge between two small Ethernet networks. The resulting network acted just like a single wired one, supporting Microsoft File and Printer Sharing and access to the Internet via my main router for multiple wired clients on both sides of the wireless WET11-to-WET11 bridge.
But when I set up another test network with one WET11 in Infrastructure mode connecting to a "normal" Access Point, I found that Microsoft File and Printer Sharing worked fine, but that I was unable to connect to anything outside my LAN, i.e. the Internet. At first I thought this was just the price you had to pay for the MPLS magic inside the WET11. But after reporting my results to Linksys, they asked me to hold off for a few days, and came back with a firmware update that fixed the problem. So be sure that you check the firmware revision of your WET11, and if it's not 1.3.2 or higher, go get the firmware update and run it. Unfortunately you'll need a Windows machine to run the update... another thing I hope Linksys fixes in future firmware releases.
Updated 11/13/02
NOTE: I missed the significance ot the WET11's ability (when set to Infrastructure mode) to connect to most (any?) Access Point, because I thought the WAP11's "AP Client" mode did the same thing. But several readers have pointed out that the WAP11 "AP Client" mode works only with other WAP11s in AP mode. I apologize for my oversight!