rmmod the rtl8187 module before proceeding:

ifconfig wlan0 down	 
rmmod rtl8187

Move /lib/modules/k#/kernel/drivers/net/wireless/mac80211/rtl818x/rtl8187.ko to a safe place. The “k#” and/or other parts of the path will be different for your distribution/system. Use “locate 8187.ko” or “find /lib/modules -name *8187*” to find the full path.

wget http://dl.aircrack-ng.org/drivers/rtl8187_linux_26.1010.zip
unzip rtl8187_linux_26.1010.zip
cd rtl8187_linux_26.1010.0622.2006/
wget http://patches.aircrack-ng.org/rtl8187_2.6.24v3.patch
tar xzf drv.tar.gz
tar xzf stack.tar.gz
patch -Np1 -i rtl8187_2.6.24v3.patch
make
make install

Now reboot your system. If your card is connected then wlan0 should now be listed in iwconfig.

Please note that a copy of the patch is also included with the aircrack-ng tar file in the “patches” subdirectory.

The transmit power can be adjusted using:

 iwconfig wlan0 txpower <value of 0 to 35>

With 0 being the lowest and 35 being the highest transmit power. The default is 5 which is normal. In order to use higher values, you must first “enable” the high power option. See the next section regarding how to do this. WARNING: Enabling high power can damage or destroy your wireless device. Use this feature at your own risk.

It is important to understand that the values are relative power values, not absolute. Meaning that they do not refer to dBm or mW values.

To view the current setting enter:

 iwlist wlan0 txpower

The system responds with the current setting:

 wlan0     unknown transmit-power information.
 
        Current Tx-Power=5 dBm        (3 mW)

You MUST ignore the dBm and mW labels. The value of “5” above is the actual value in the 0 to 35 range. Unfortunately due to driver constraints, the “dBm (3mW)” are also displayed but must be ignored.

+++++++++ WARNING +++++++++
+++++++++ WARNING +++++++++
WARNING: Enabling high power can damage or destroy your wireless device. Use this feature at your own risk.
+++++++++ WARNING +++++++++
+++++++++ WARNING +++++++++

Starting with the rtl8187_2.6.24v3.patch, there is a iwpriv “highpower” setting you need to set to “1” in order to increase the txpower over the default value.

To enable high power:

 iwpriv wlan0 highpower 1

To disable high power:

 iwpriv wlan0 highpower 0

Although it is highly recommended that you patch the driver, it is possible to use the unpatched driver for injection. Simply enter this command first “iwpriv wlan0 rawtx 1”.

Running “sh wlan0up” fails.

Solution:
Make sure your ieee80211 stack is built as a module and remove all those modules. If it is integrated in the kernel, rebuild your kernel with a modular ieee80211 stack.

Trying to run “sh wlan0up” gives you an error of wlan0 device not existing. lsusb indicates that the wireless card is connected.

Solution:
You sometimes get this message when another driver, which also creates an wlanX interface is loaded before the r8187 driver. Examples: acx111 or hostap. In such a case the rtl8187 device will be wlan1 or wlan2. Look at iwconfig to see if there is such an interface and use that one instead.

The following errors were on Ubuntu:

insmod: error inserting 'ieee80211_crypt-rtl.ko': -1 Invalid module format
insmod: error inserting 'ieee80211_crypt_wep-rtl.ko': -1 Unknown symbol in module
insmod: error inserting 'ieee80211_crypt_tkip-rtl.ko': -1 Unknown symbol in module
insmod: error inserting 'ieee80211_crypt_ccmp-rtl.ko': -1 Unknown symbol in module
insmod: error inserting 'ieee80211-rtl.ko': -1 Unknown symbol in module
insmod: error inserting 'r8187.ko': -1 Unknown symbol in module

Solution:

cd beta-8187
rm -f Modules.symvers
ln -s ../ieee80211/Modules.symvers Modules.symvers
### NOTE versions of GCC may require this instead: ln -s ../ieee80211/Module.symvers Module.symvers
cd ..
sh makedrvbk

Messages below when compiling the RTL8187 driver on Ubuntu 6.10 with 2.6.17-11 generic (patched for Nvidia) kernel.

WARNING: "ieee80211_wx_get_name_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!
WARNING: "free_ieee80211_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!
WARNING: "ieee80211_wx_get_freq_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!
WARNING: "alloc_ieee80211_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!
#many messages suppressed...
WARNING: "ieee80211_wx_get_scan_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!
WARNING: "ieee80211_wx_set_rate_rtl7" [/root/drivers/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.ko] undefined!

Generally, warnings can be ignored. To eliminate the ones above, follow the instructions in the previous troubleshooting tip. IE Remake the link to Modules.symvers and then re-compile.

Compiling results in an error similar to:

make: *** /lib/modules/2.6.15-28-386/build: No such file or directory.
#Plus other references to "No such file or directory."\\

Solution:
See installing missing packages.

While loading the modules you get an “Operation not permitted” message similar to:

insmod: error inserting 'ieee80211_crypt-rtl.ko': -1 Operation not permitted
insmod: error inserting 'ieee80211_crypt_wep-rtl.ko': -1 Operation not permitted
insmod: error inserting 'ieee80211_crypt_tkip-rtl.ko': -1 Operation not permitted
insmod: error inserting 'ieee80211_crypt_ccmp-rtl.ko': -1 Operation not permitted
insmod: error inserting 'ieee80211-rtl.ko': -1 Operation not permitted
insmod: error inserting 'r8187.ko': -1 Operation not permitted
wlan0: ERROR while getting interface flags: No such device

Solution: You must be root to load the modules. You “su” to root then load the modules. On many distributions, you can also do this by using sudo plus the script name.

You receive a compile error messages similar to one or more of:

• /usr/src/redhat/BUILD/rtl8187_linux_26.1025.0328.2007/ieee80211/ieee80211_rx.c:46:26: error: linux/config.h: No such file or directory
• /usr/src/redhat/BUILD/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187.h:50:26: error: linux/config.h: No such file or directory
• “linux/config.h no such file or directory…”.
• In French: “erreur: linux/config.h : Aucun fichier ou répertoire de ce type”.

Solution: You need to create an empty file called linux/config.h in the kernel source directory. The simplest way is:

“touch /usr/src/kernels/2.6.18-1.2869.fc6-i686/include/linux/config.h”

Change “/usr/src/kernels/2.6.18-1.2869.fc6-i686” to where your kernel sources are located and the your specific kernel and directory structure. You can use “uname -r” to help determine your exact kernel.

You get compile errors similar to:

/root/rtl8187_linux_26.1025.0328.2007/ieee80211/ieee80211_softmac.c:2168:78: error: macro "INIT_WORK" passed 3 arguments, but takes just 2
/root/rtl8187_linux_26.1025.0328.2007/ieee80211/ieee80211_softmac.c: In function ‘ieee80211_softmac_init’:
/root/rtl8187_linux_26.1025.0328.2007/ieee80211/ieee80211_softmac.c:2168: error: ‘INIT_WORK’ undeclared (first use in this function)

and so on…

/root/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187_core.c:1625:64: error: macro "INIT_WORK" passed 3 arguments, but takes just 2
/root/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187_core.c: In function ‘rtl8180_init’:
/root/rtl8187_linux_26.1025.0328.2007/rtl8187/r8187_core.c:1625: error: ‘INIT_WORK’ undeclared (first use in this function)

and so on…

Solution: This typically occurs after you have upgraded your kernel version. Delete the all the patch files and install a fresh version. You should now be able to compile it successfully. Also ensure that you have matching kernel header files.

Many people complain that they only get injection rates of about 50 packets per second. Here are few items which are known to cause this:

• Using VMware Workstation 5.x or earlier. Be sure to use VMware Workstation 6 or above. The root cause is that older versions (< 6.0) use the old USB standard.
• Using VMware Players earlier then version 2. Be sure to use VMware Player 2 or above. The root cause is that older versions (< 2.0) use the old USB standard.
• Using pre-2.0 USB standard hardware. Make sure you are using hardware with support for USB 2.0.
• Having legacy USB support enabled in your BIOS. Try disabling this option.

Note: VMWare Workstation < 6.0 and VMWare Player < 2.0 use USB 1.1 and when injecting at high speed, injection uses all USB bandwith (so, nearly no packets are received) and you can notice a lot of packets lost in airodump-ng.

Some people have reported that including “-x 250” on the aireplay-ng command optimizes their injection rates. You will have to experiment to see if this helps you or not.

While in monitor mode, airodump-ng will not capture or record any packets injected by the aircrack-ng suite. This is a known problem with the driver.

You receive one or more errors similar to:

• Attempting to setup SKA mode: “iwconfig wlan0 mode managed key 1234567890 restricted” results in:

Error for wireless request “Set Encode” (8B2A) :

 SET failed on device wlan0 ; Operation not supported.

• ieee80211_auth_challenge_rt17+0x2fe/0x310 [ieee80211_rtl] kernel panic

SKA is not currently supported with the RTL8187 driver. There is no known workaround.