The second Airport Express is out in my office, in a separate building 50 feet away. An ethernet cable runs in a conduit underground from the office to the house, where it connects to a wall jack. A cable from this jack runs to a port in my Airport Extreme. Unfortunately, I am not able to get this office Airport Express to work properly.
Have you tested this connection to make sure things are working? In other words, power down the AirPort Express and connect your computer directly to the ethernet cable from the main router. Try to log on and get on the Internet. Be sure to turn off the wireless on the computer when you run this "test"
Can you do this?
Just the person I was hoping would respond! Thanks for this.
To my embarrassment, I went out to the office, plugged the ethernet cable directly into my Macbook Pro, and discover that I am still Internet-free. In network prefs it says something about a self-assigned IP address. I tried refreshing dhcp and using a different "location," both to no avail. This is a puzzle; I've never had such a problem before.
I don't think it's the cable, since earlier this morning I was able to see both AX and Airport Extreme on my internal network.
Please leave the AirPort Express off for now, and then perform a complete power cycle of your entire network as follows:
Power everything off...modem, main router, computers, printers, all devices. Order is not imporant here
Wait a moment, then power up the modem first and let it run a moment or two by itself
Then power up the AirPort Extreme the same way
Power up each device (leaving the AirPort Express off) the same way until everything is powered back up
Perform the same test again by turning off the wireless on your computer or laptop and connecting to the ethernet cable that runs back to the AirPort Extreme.
Can you connect to the Internet now?
If no, please move the laptop very close to the AirPort Extreme and connect to the Extreme using a short ethernet cable. Can you connect now?
If yes, then I suspect a bad or intermittent connector on the "long" ethernet cable. You'll need to get that addressed first by replacing one or both connectors on either end.
Then test at the end of the "long" ethernet cable again with your laptop to make sure that you can connect to the Internet. Obviously, we cannot proceed with the AirPort Express configuration until you have a reliable Internet connection out in the remote building.
Bob, thanks a million for prompting me to investigate this. I discovered that the cable running from the Airport Extreme to the wall jack (where the it meets the crucial office connection) ran through a Linksys switch and was plugged into the "uplink" port. I switched it to one of the regular ports and voila, everything works!
I have no idea if an uplink port is special in some way, or if it's just a bum port, but I am very grateful for your help on this, as well as your clear instructions in other threads on setting up a roaming network.