Airport express 802.11g does not work with Airport extreme base station 802.11n 5th gen
I have an Airport extreme 802.11n 5th gen, trying to add Airport express 802.11g onto my network. I followed the instructions to add the airport express to the existing network (radio mode is automatic) , however when i plug a device into the express ethernet port there is no connection (light on the express is green) but no ethernet connection. Is my extreme base station or express configured wrong or they not compatible? This is suppose to be easy...
Also do I need to set up WDS, I am using AirPort Utility 5.6, and there is no option for WDS
Thanks in advance for your assistance
AirPort Express Base Station, Mac OS X (10.7.3), AirPort Extreme Base Station