Problem merging .ivs

[JJtRvXX]

Hi to all the friends of the forum, i'm trying to crack a wep key using a centrino ipw2200 with packet injection patch installed (and working i've tried on my company wireless network). I've launched this attack:

sudo aireplay-ng -3 -b <MAC AP> -h <My MAC> -i rtap0 eth1

and then captured packets with airodump-ng: the first problem is that when the number of packets is around 900.000 ivs the capture process become very slow..only 1 or 2 packets per second. I've thought to break the capturing process then restart it and merging the resultant files but here is the second problem: when i merge the files using

ivstools --merge myfiles1.ivs myfiles2.ivs total.ivs

the total.ivs file is not the sum of all the files but only a few packets bigger than the original files 

For example to better explain:

myfiles1.ivs -> 900.000 ivs
myfiles2.ivs -> 900.000 ivs

total.ivs -> 920.000 ivs

What's goning wrong?

I've tried to capture .ivs file in different days but the resulting merge is the same..then if I start:

sudo aircrack-ng -0 *.ivs

the amount of packets is the same of the merging process 

I've launched and tried to crack with aircrack-ng for 1 day but with no luck...I'm capturing valid packets?I'm trying to crack an Access Point with no client is this the problem??

Now i'm trying the chop chop attack too but the resultant ivs files have the same problem in merging and with the aircrack...please i need help

thanks in advance

JJtRvXX

[Mister_X]

Both files contains nearly the same IVs.

[JJtRvXX]

Thanks for the answer...how can i obtain different ivs???Why this happens??I've tried with my company wireless network without problem maybe because there isn't client on the network???

JJtRvXX

[JJtRvXX]

Is it possible that every day i capture the same ivs please any suggestion?

JJtRvXX

[Mister_X]

try to attack the client (you don't decide which IVs you want: you can't ask the AP "I want other IVs")

[JJtRvXX]

Thanks for your reply, unluckily the AP hasn't client 
Do you have any suggestion about the strange behaviour of the AP??(After 900.000 ivs packets the capture process become very very slowly)

Thanks in advance

JJtRvXX

[ASPj]

Well, some old Cisco APs have a fixed 0 in all of their IVs.
They stop at about 130.000 IVs. Its an already discussed thing here. If you are lucky, these 90.000 IVs are enough, for the Cisco APs 130.000 IVs is almpst always enough too, because the 0 generates more weak IVs then usually