AP cannot get online on AC

while I'm deploying my wireless network, the capwap tunnel can not be built, what should I check ?

(1) Communication between the AP and the AC is abnormal.
1. AP fails to get the IP address.
2. AP fails to get the Option 138 field.
3. AP fails to ping the AC to create the tunnel.
4. CAPWAP UDP ports 5246 and 5247 are discarded or filtered out by anintermediate device.


(2) AC and AP are in abnormal status.
1. AP cannot go online due to a high AC CPU usage.
2. AC and AP version span is large (10.x and 11.x).
3. AP name is not unique.


(3) after checked these information, if the problem still exists, you can use " show ap-config summary deny-ap " to check the cause.
By bind-ap-mac  //Indicates that the AP-MAC binding is rejected. The cause is that the MAC whitelist bind-ap-mac is enabled on the AC but theMAC of this AP does not exist in ap-config.
By wtp-limit       //Indicates that the maximum number of online APs has reached. A common cause is that the license is insufficient or the maximum number of online APs has reached. It is rarely caused by the wtp-limit configuration.
By conflict         //Indicates that the AP name conflicts with the MAC name. It is because the AP name has already existed on the AC or other APsof this MAC are online or configured.
By ap-auth         //Indicates that the AP certification is restricted. Certification by serial number or password is enabled on the AC but the AP does not carry any certification information.  
By vendor id      //Indicates that the interconnection is not supported because the AP of another vendor is used.