try aireplay-ng -2 -p 0841 attack you can see whole code on aircrack-ng wiki.
This can help not all ap have same behaviour.
also try clientless wep attack. For this use: fragmentation and chop chop attack this can use when there is only wired client. So then you will have larger picture what all types of attack can someone use in wep cracking and also pros and cons and when is some attack good and when not.
P.s. - why you change your mac its not nessecary if you dont have mac filter enabled and if you control your lab this can help bad guys to hide his real mac making forensics job harder.
Dont just retype code from other tutorials not knowing what is for what.


) but had forced traffic from multiple clients by simultaneously downloading large iso files.
C:CE) on channel 1

