bioneural.net

Having spent the better part of two half days trying to achieve the impossible, I wish to recount an exercise in wireless frustration. The challenge was to hook up an iMac G4 (Flat Panel) with no Airport Card, located in the attic room, to my home LAN (and thus to the Internet). One purpose of this machine was to serve as a screen for streamed video that could be watched while using the exercise cycle. A TV had provided such distraction, but that had broke. To cement the challenge, the problem should be solved using equipment already to hand i.e. at no additional cost.

My "BeBox", the hub of my home LAN, is actually a SpeedTouch 780WL WiFi router/ ADSL modem. The router's wireless access point (WAP) offers 802.11b/g, which is secured with Wi-Fi Protected Access (WPA) encryption—the earlier Wired Equivalent Privacy (WEP) standard is considered insecure.

A slow, insecure option that worked

It's worth noting that the original Apple Aiport Card appropriate for this machine can still be had on eBay for £30–40. Although this card is WPA-aware, it is only 802.11b (11Mbps) and thus not suitable for streaming. I know this to be so because the first device I tried was the Linksys WET11, a wireless Ethernet bridge. For the record, because it took me some time to discover, this device has a factory-default IP of 192.168.1.225. However, before you can connect to it using Safari (or any other browser), you need to manually assign your Mac an IP address in the same range and subnet (255.255.255.0).

Wireless bridging between the BeBox and WET11 "just worked", without any complicated configuration. However, video streamed locally from/to VLC was intermittently pixelated and my 17Mbps downstream broadband was somewhat choked for streaming Internet video.

A fast, secure option that didn't work

I also had an Apple AirPort Express (AX) lying around. As Apple state in their configuration walkthrough for Mac OS X 10.4 (Tiger):

Using the wireless distribution system (WDS) feature, you can set up two to five base stations as a unified network that shares one Internet connection.

WDS sounded ideal, giving an expensive and complex Apple product the functionality of a cheap and simple wireless Ethernet bridge. I factory-reset the AX and consulted various online descriptions and found this one most helpful.

I had to configure the AX for WDS on another Mac running Leopard because AirPort Admin Utility on the iMac, although running Tiger, warned "Joining a WPA-protected network and making changes to a WPA-protected base station requires a WPA capable computer. This computer is not WPA capable. If you continue you will not be able to join the WPA-protected network or make changes to the WPA-protected base station."

After much wasted effort, with Google's assistance I learned that the SpeedTouch 780 doesn't support the combination of WDS and WPA, although will work with WDS and WEP. Downgrading my network security to WEP 24/7 is just too much of a compromise.

A fast, part-time insecure option that worked

Because I wasn't configuring WPA, I set up the AX from the iMac—so the following screen captures reflect AirPort Admin running under 10.4.11. First up, the AirPort tab:

1. Name your AX base station;
2. Change the AX password;
3. Set Wireless Mode to Create a Wireless Network;
4. Name your AX network;
5. Do not enable wireless security (unless you want to use WEP, which is nearly the same as using none);
6. Set the Channel to the same channel your SpeedTouch 780 is using;
7. Check Create a closed network.

Next is the Internet tab:

1. Connect using AirPort (WDS);
2. Enter the MAC (physical) address of your WAP (see Home > Home Network > Interfaces > WLAN: [YourWLAN]);
3. Uncheck Also allow wireless client computers (we only want the hard-wired iMac to connect);
4. Configure using DHCP (the iMac and AX will be assigned IP addresses by the SpeedTouch).

Now comes the Network tab:

1. Make sure Distribute IP addresses is unchecked.

Finally, the WDS tab:

1. Check Enable this base station as a remote base station;
2. Confirm the MAC address of your main router is shown;
3. Click Update to restart the AX.

One more step. I also needed to enable WDS for the AirPort in the SpeedTouch settings. Make sure WDS is enabled and check the box next to your AX base station name and click Apply:

It now works—but only if I temporarily disable encryption (both network names remain hidden, however, and new wireless clients are not allowed). Sometimes, no matter how persistent you may be, you can't have everything.

Actions Send this article link by e-mail Print this article without other content Follow responses to this article (comments feed) Share this on del.icio.us, Digg, StumbleUpon Translate this page: DE | ES | FR Follow tag feeds: howto, Mac, network, router, security, streaming, wifi. Buy for yourself on Amazon.com or Amazon.co.uk, leave a "tip"