On a cisco aironet 1130ag series standalone access point,the status led is dark blue and blinking.
What does this indicate？（）

In a deployment using standalone access points， clients set up to authenticate with eap-peap or eap-cisco wireless （cisco-leap） cannot authenticatE.  when you inspect the failed attempts report on the cisco secure acs， you find this error： "unknown network access server nas." 
Which problem may have caused this failure？（）