Debugging Tools - MIA
Linksys must have great faith in the WRE54G's Auto configuration and Setup Wizard features to get the Expander up and expanding your wireless LAN's range, because they included only one feature to help you determine whether there is a problem with the product. The lone warning you'll get is that if the signal is lost from the WRE54G's bridged companion, the Link light will change from steady blue to steady red.
This feature isn't foolproof, however. It worked properly when I powered off a properly linked AP and turned on a different one, with the WRE54G's light staying red. But when I enabled WEP on the Expander's programmed bridging partner (leaving the Expander's WEP disabled) the light stayed blue, but of course the link was really down.
If you have problems, the only help offered in the User Guide's Troubleshooting section is basically to power cycle, reset to factory defaults and re-Auto configure the unit. Nowhere is there even a mention of how to verify that the little bugger is even working (a ping to the WRE54G's IP address from a client associated to a bridged AP will do it), or tell when traffic is flowing through the Expander (just watch the Activity light). I'd at least like to see an indication of signal strength and transmit rate to the WRE54G's bridging partner added to the Web interface. Receive and transmit data statistics would be nice, although not as helpful.
Forget finding any help in positioning the WRE54G for optimum performance, too, since the only tip offered is that "the best placement is usually at the edge of your wireless network". While this advice may help ensure that your wireless client latches onto the Expander instead of your main AP, it's guaranteed to give you slower performance.
The reason is that placing the Expander at the WLAN fringe will cause the transmit rate to its bridge partner to run at reduced speed, with whatever transmit rate negotiated between the two (you can't set this manually) cut at least in half by the double duty that the single radio must perform for WDS to work. Since the wireless chain is only as fast as its slowest link, it won't matter that your wireless client tells you that you have a 54Mbps connection to the WRE54G, if the WRE54G to AP link is running at 11Mbps!
Finally, I don't understand Linksys' decision to not expose WDS bridging controls on its wireless routers, other than to preclude consumers from using non-Linksys WDS-based products to connect to their routers, or to perpetuate the confusion that surrounds wireless bridging and repeating in general. Exposing the controls won't necessarily ease setup, but at least users would be able to check settings and understand how the product is really configured.