Currently Being ModeratedFeb 17, 2013 12:58 PM (in response to jerryroundel)
The Guest Network will not be be able to connect to the Internet unless your AirPort Express is configured to act as the "main" router on the network....not as a "bridge".
We need to check some settings, to see how your AirPort Express is configured.
If you are using AirPort Utility 6.x, open the application and click on the AirPort Express icon, then click Edit
Click the Network tab at the top of the next next window and check the setting for Router Mode.
Report on your findings.
If you are using the older AirPort Utility 5.x, open the application and click on the AirPort Express, then click Manual Seup
Click the Internet icon, then click the Internet Connection tab
What is the setting for Connection Sharing that you see there?
Currently Being ModeratedFeb 17, 2013 1:25 PM (in response to jerryroundel)
Now, unfortunately you likely have a Double NAT error on the network. Hopefully, you will be able to "ignore" it, but this error does have a way of coming back to bite you later. The AirPort may revert to Bridge Mode...so keep an eye on things.
Currently Being ModeratedFeb 18, 2013 12:31 AM (in response to Bob Timmons)
I have a Double NAT error since my ISP added a router in front of my Airport. I never had problems with it, as long as both operate in a different IP range.
You can tell the Airport to ignore this error with the Airport Utility. Open it and go were it shows the status. Double clicking it gives a dialog with all active errors. In the checkboxes for each error you can tell the airport to ignore that type of errors, and the light on the airport turns to green again. That way it is easier to detect a new error when the light turns amber again.