1、当我们部署完ME的时候，发现有一些AP虽然显示已经加入了WLC（ME），但是它其实并没有正常的工作，显示不可用：
(Cisco Controller) >show ap su
Number of APs.................................... 2
Global AP User Name.............................. Not Configured
Global AP Dot1x User Name........................ Not Configured
* prefix indicates Cisco Internal AP
AP Name Slots AP Model Ethernet MAC Location Country IP Address Clients DSE Location
------------------------------ ----- -------------------- ----------------- -------------------- ---------- --------------- ------- --------------
*BJSL-1240680-AP1 2 AIR-AP1852I-H-K9 18:8b:45:0a:03:00 default location CN 192.168.111.11 0 [0 ,0 ,0 ]
AP1 2 AIR-CAP1702I-H-K9 88:1d:fc:3a:b2:14 default location 192.168.111.10 0 [0 ,0 ,0 ]
(Cisco Controller) >show ap join stats summary all
Number of APs.............................................. 2
Base Mac AP EthernetMac AP Name IP Address Status
18:8b:45:0a:74:c0 18:8b:45:0a:03:00 BJSL-1240680-AP1 192.168.111.11 Joined
a0:ec:f9:50:a7:30 a0:ec:f9:50:a7:30 AP1 192.168.111.10 Joined
这个时候，我们需要部署一个外部的server以供在线的设备去升级对应的版本，以加入ME正常工作：
如上配置信息Save之后，对应的设备将会自动从TFTP server下载需要的镜像。
对应的AP更换完成后，会重新加入WLC：
(Cisco Controller) >show ap summary
Number of APs.................................... 2
Global AP User Name.............................. Not Configured
Global AP Dot1x User Name........................ Not Configured
* prefix indicates Cisco Internal AP
AP Name Slots AP Model Ethernet MAC Location Country IP Address Clients DSE Location
------------------------------ ----- -------------------- ----------------- -------------------- ---------- --------------- ------- --------------
*BJSL-1240680-AP1 2 AIR-AP1852I-H-K9 18:8b:45:0a:03:00 default location CN 192.168.111.11 0 [0 ,0 ,0 ]
AP1 2 AIR-CAP1702I-H-K9 88:1d:fc:3a:b2:14 default location CN 192.168.111.10 0 [0 ,0 ,0 ]
此时就可以正常使用了。