我有两台电脑：
- Ubuntu 12.04.4、3.5.0-45-generic（我们称之为“myGoodPC”）
- Ubuntu 12.04.3、3.8.0-35-generic（我们称之为“myBadPC”）
myBadPC在ESXi 5.0.0的虚拟机中运行。
在myGoodPC我设法正确配置无线接口：
root@myGoodPC:~# sudo iw --debug dev wlan0 set channel 10 HT40-
-- Debug: Sent Message:
-------------------------- BEGIN NETLINK MESSAGE ---------------------------
[HEADER] 16 octets
.nlmsg_len = 44
.nlmsg_type = 24 <0x18>
.nlmsg_flags = 5 <REQUEST,ACK>
.nlmsg_seq = 1398703424
.nlmsg_pid = 14796
[PAYLOAD] 28 octets
02 00 00 00 08 00 03 00 08 00 00 00 08 00 26 00 99 09 ..............&...
00 00 08 00 27 00 02 00 00 00 ....'.....
--------------------------- END NETLINK MESSAGE ---------------------------
-- Debug: Received Message:
-------------------------- BEGIN NETLINK MESSAGE ---------------------------
[HEADER] 16 octets
.nlmsg_len = 36
.nlmsg_type = 2 <ERROR>
.nlmsg_flags = 0 <>
.nlmsg_seq = 1398703424
.nlmsg_pid = 14796
[ERRORMSG] 20 octets
.error = 0 "Success"
[ORIGINAL MESSAGE] 16 octets
.nlmsg_len = 16
.nlmsg_type = 24 <0x18>
.nlmsg_flags = 5 <REQUEST,ACK>
.nlmsg_seq = 1398703424
.nlmsg_pid = 14796
--------------------------- END NETLINK MESSAGE ---------------------------
我还成功嗅探 WiFi 数据包（ICMP / ping 数据包）。
尝试配置时出现myBadPC错误：
root@myBadPC:~# sudo iw --debug dev wlan0 set channel 10 HT40-
-- Debug: Sent Message:
-------------------------- BEGIN NETLINK MESSAGE ---------------------------
[HEADER] 16 octets
.nlmsg_len = 44
.nlmsg_type = 25 <0x19>
.nlmsg_flags = 5 <REQUEST,ACK>
.nlmsg_seq = 1398698982
.nlmsg_pid = 14533
[PAYLOAD] 28 octets
02 00 00 00 08 00 03 00 03 00 00 00 08 00 26 00 99 09 ..............&...
00 00 08 00 27 00 02 00 00 00 ....'.....
--------------------------- END NETLINK MESSAGE ---------------------------
-- Debug: Received Message:
-------------------------- BEGIN NETLINK MESSAGE ---------------------------
[HEADER] 16 octets
.nlmsg_len = 64
.nlmsg_type = 2 <ERROR>
.nlmsg_flags = 0 <>
.nlmsg_seq = 1398698982
.nlmsg_pid = 14533
[ERRORMSG] 20 octets
.error = -16 "Device or resource busy"
[ORIGINAL MESSAGE] 16 octets
.nlmsg_len = 16
.nlmsg_type = 25 <0x19>
.nlmsg_flags = 5 <REQUEST,ACK>
.nlmsg_seq = 1398698982
.nlmsg_pid = 14533
--------------------------- END NETLINK MESSAGE ---------------------------
command failed: Device or resource busy (-16)
显然，在此命令之后我无法嗅探数据包（ICMP/ping）（但广播可见）。
注意：为了清楚起见，我从上面的代码中删除了其他命令（例如ifconfig wlan0 down之前iw或iwconfig wlan0 mode monitor之后ifconfig wlan0 up的命令）。
什么可能导致 wlan0 出现错误myBadPC？