Just in case somebody else ran into the same issue, I managed to solve it by installing pypcap module to replace pcapy. I referred to http://comments.gmane.org/gmane.comp.security.scapy.general/4026
you will need to have the following dependencies installed:
- C compiler + make (Xcode will have these settled)
- libpcap
- pyrex ( can be installed by package manager e.g., pip ).
you might run into an issue when you install pypcap
after the dependencies are installed, refer to this patch http://code.google.com/p/pypcap/issues/detail?id=13, it worked for me!