Hi all...
gr8 work...

ok we are... I'm trying to install madwifi-ng patch for aircrack-ng.
I have a 3com pcmcia (3CRPAG175B) with atheros AR5413 chip.

I've seen that to use this kind of chip we must patch aircrack-ng suite with the patch present on their website...
but when i try to install i recieve this kind or error...
Code:
bt ~ # ifconfig ath0 down
ath0: ERROR while getting interface flags: No such device
bt ~ #  cd madwifi-ng
bt madwifi-ng #  patch -Np1 -i ../madwifi-ng-r3386v3.patch
patching file ath/if_ath.c
Reversed (or previously applied) patch detected!  Skipping patch.
3 out of 3 hunks ignored -- saving rejects to file ath/if_ath.c.rej
bt madwifi-ng #  ./scripts/madwifi-unload
bt madwifi-ng # make
/bin/sh: line 0: cd: /lib/modules/2.6.21.5/build: No such file or directory
Makefile.inc:66: *** /lib/modules/2.6.21.5/build is missing, please set KERNELPATH.  Stop.
bt madwifi-ng #
ok i've read that we need the header and the .config file and the build directory...
I'm new for this kind of problem... so someone can help me?

thank ahead of time...