It seems that the filter
of sniff
function does not work properly.
I m executing the sniff with the following filter
a=sniff(co
You can check into the syntax of filters in the following site http://biot.com/capstats/bpf.html. I was facing similar kinds of problems and it worked for me.
You might like to refer to this question: https://stackoverflow.com/questions/37453283/filter-options-for-sniff-function-in-scapy#=
You can also try to test your program by opening the required ports before running code.