AIR-LAP1242AG-C-K9, 1242的瘦AP。以1242AP为例，1131和1252做法同样
1、首先准备回退到胖AP的镜像文件。我拿到的是一个 “c1240-k9w7-tar.124-10b.JA3.tar”的tar包压缩文件。
2、准备TFTP的环境。（还是用3CDaemon吧，今天曾经用过另外两个tftp软件，同样的条件都无法更新成功。而且3CDaemon还可以随时看到监控记录，便于分析问题），把目录指向要升级的镜像目录。
TFTP的服务器主机ip地址设置为10.0.0.2 255.0.0.0 镜象文件改名为“c1240-k9w7-tar.default”(IP地址和镜像文件名这样改从后面的提示中可以知道是为什么)
3、超级终端、控制口连接到AP，以便监控状态。
4、按住ap上的mode键，然后插上电源，稍等一会，出现如下提示
flashfs[0]: 3 files, 2 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 15998976
flashfs[0]: Bytes used: 1867776
flashfs[0]: Bytes available: 14131200
flashfs[0]: flashfs fsck took 26 seconds.
Base ethernet MAC Address: 00:1d:a1:ff:3c:dc
Initializing ethernet port 0...
Reset ethernet port 0...
Reset done!
ethernet link up, 100 mbps, full-duplex
Ethernet port 0 initialized: link is up
button is pressed, wait for button to be released...
看到上面wait的提示后，松开mode键
button pressed for 29 seconds
process_config_recovery: set IP address and config to default 10.0.0.1
process_config_recovery: image recovery
image_recovery: Download default IOS tar image tftp://255.255.255.255/c1240-k9w7-tar.default
examining image...
出现上面提示。（从这里可以看出，在这个状态下，ap把自己的以太口设置为10.0.0.1的ip地址，然后广播去找tftp服务器下的c1240-k9w7-tar.default镜像文件）
如果上述设置正确的话，就会开始更新了。
5、更新时的屏幕显示如下：
extracting info (275 bytes)
Image info:
Version Suffix: k9w7-.124-10b.JA3
Image Name: c1240-k9w7-mx.124-10b.JA3
Version Directory: c1240-k9w7-mx.124-10b.JA3
Ios Image Size: 4813312
Total Image Size: 5560832
Image Feature: UNKNOWN
Image Family: C1240
Wireless Switch Management Version: 1.0
Extracting files...
extracting info (275 bytes)
c1240-k9w7-mx.124-10b.JA3/ (directory) 0 (bytes)
............................
extracting c1240-k9w7-mx.124-10b.JA3/info (275 bytes)
extracting info.ver (275 bytes)
Deleting current version...
Deleting flash:/c1240-rcvk9w8-mx...done.
New software image installed in flash:/c1240-k9w7-mx.124-10b.JA3
Configuring system to use new image...done.
Requested system reload in progress...download took about 408 seconds
Loading "flash:/c1240-k9w7-mx.124-10b.JA3/c1240-k9w7-mx.124-10b.JA3"...##################
File "flash:/c1240-k9w7-mx.124-10b.JA3/c1240-k9w7-mx.124-10b.JA3" uncompressed and installed, entry point: 0x3000
executing...
6、到此已经可以了，你等着AP启动完全。你就可以用console口登陆，和配置交换机一样配置；或者配置一个IP address
interface BVI1
ip address 192.168.1.5 255.255.255.0
no ip route-cache
!
ip default-gateway 192.168.1.254
此时就可以登陆WEB界面经行配置。Cisco默认用户密码为Cisco
本文转自 bilinyee博客，原文链接： http://blog.51cto.com/ericfu/1782241 如需转载请自行联系原作者
