我尝试启动 hostapd，但没有成功。我使用的是 Headless Ubuntu 11.10 oneiric 3.0.0-16-server x86_64。WLAN 驱动程序是 rt2800usb，我的无线网卡 TP-Link TL-WN727N 支持 AP 模式，如下所示：
us0# ifconfig wlan0
wlan0 Link encap:Ethernet HWaddr 00:27:19:be:cd:b6
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
us0# lsusb
Bus 003 Device 003: ID 148f:3070 Ralink Technology, Corp. RT2870/RT3070
Wireless Adapter
us0# lshw -C network
*-network:3
description: Wireless interface
physical id: 4
bus info: usb@3:2
logical name: wlan0
serial: 00:27:19:be:cd:b6
capabilities: ethernet physical wireless
configuration: broadcast=yes driver=rt2800usb driverversion=3.0.0-16-server
firmware=0.29 link=no multicast=yes wireless=IEEE 802.11bgn
us0# hostapd /etc/hostapd/hostapd.conf
Configuration file: /etc/hostapd/hostapd.conf
Could not read interface wlan0 # The int flags: No such device
nl80211 driver initialization failed.
ELOOP: remaining socket: sock=4 eloop_data=0xd3e4a0 user_data=0xd3ecc0 handler=0x433880
ELOOP: remaining socket: sock=6 eloop_data=0xd411f0 user_data=(nil) handler=0x43cc10
us0# cat /etc/hostapd/hostapd.conf
ssid=Home
interface=wlan0 # The interface name of the card
#driver=rt2800usb
driver=nl80211
macaddr_acl=0
ieee80211n=1
channel=1
hw_mode=g
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=88888888
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
us0# iw list
Wiphy phy0
Band 1:
Capabilities: 0x172
HT20/HT40
Static SM Power Save
RX Greenfield
RX HT20 SGI
RX HT40 SGI
RX STBC 1-stream
Max AMSDU length: 7935 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: 2 usec (0x04)
HT RX MCS rate indexes supported: 0-7, 32
TX unequal modulation not supported
HT TX Max spatial streams: 1
HT TX MCS rate indexes supported may differ
Frequencies:
* 2412 MHz [1] (20.0 dBm)
* 2417 MHz [2] (20.0 dBm)
* 2422 MHz [3] (20.0 dBm)
* 2427 MHz [4] (20.0 dBm)
* 2432 MHz [5] (20.0 dBm)
* 2437 MHz [6] (20.0 dBm)
* 2442 MHz [7] (20.0 dBm)
* 2447 MHz [8] (20.0 dBm)
* 2452 MHz [9] (20.0 dBm)
* 2457 MHz [10] (20.0 dBm)
* 2462 MHz [11] (20.0 dBm)
* 2467 MHz [12] (20.0 dBm) (passive scanning, no IBSS)
* 2472 MHz [13] (20.0 dBm) (passive scanning, no IBSS)
* 2484 MHz [14] (20.0 dBm) (passive scanning, no IBSS)
Bitrates (non-HT):
* 1.0 Mbps
* 2.0 Mbps (short preamble supported)
* 5.5 Mbps (short preamble supported)
* 11.0 Mbps (short preamble supported)
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
max # scan SSIDs: 4
Supported interface modes:
* IBSS
* managed
* AP
* AP/VLAN
* WDS
* monitor
* mesh point
Supported commands:
* new_interface
* set_interface
* new_key
* new_beacon
* new_station
* new_mpath
* set_mesh_params
* set_bss
* authenticate
* associate
* deauthenticate
* disassociate
* join_ibss
* Unknown command (68)
* Unknown command (55)
* Unknown command (57)
* Unknown command (59)
* Unknown command (67)
* set_wiphy_netns
* Unknown command (65)
* Unknown command (66)
* connect
* disconnect
问题是：为什么 hostapd 没有启动？
答案1
答案很简单：删除"interface=wlan0"in之后的所有内容（空格、注释等）。/etc/hostapd/hostapd.conf文件 并使用driver=nl80211.