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Cracking WEP using pcap-getIV.pl - Datalinktype not supported error

Hi all,

Im trying to run some of the well known wep cracking algorithms on my home wep network.

Currently, im running tcpdump to dump packet data from my airport express to a file packets.pcap using the following command:

tcpdump -w packets.pcap -i 'en1' -y EN10MB

I then run pcap-getIV.pl to extract weak IV's from the captured data using:

perl pcap-getIV.pl -f packets.pcap -b 13

However, this returns the error:

DLT = 1: unsupported DLT type at pcap-getIV.pl line 190.

The pcap-getIV.pl file will accept only 2 datalink types, either IEEE802_11 or Prism 2:

if ($dlt eq 105) {
      print("DLT_IEEE802_11 (0byte Offset)\n");
} elsif ($dlt eq 119) {
      print("Prism2 Header (144byte Offset)\n");
} else {
      die("unsupported DLT type");

However, when i try to run tcpdump with the datalinktype as IEEE802 i get the error:
tcpdump: IEEE802 is not one of the DLTs supported by this device

How can i dump packets using the supported datalink types of the pcap-getIV.pl script?

Surely Airport Express supports IEEE802 !!!

1 Solution
you could try Ethereal (http://ethereal.com/download.html)...looks like they have a fink version (u may need to install the package manager "fink", but it's pretty slick) or it also looks like they have a darwin port (OSX 10.2)...or you could always compile from source

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