printf " header length: %d * 32 bit words\n" hdrlen;
printf " type of service: %d\n" tos;
printf " packet length: %d bytes\n" length;
printf " header length: %d * 32 bit words\n" hdrlen;
printf " type of service: %d\n" tos;
printf " packet length: %d bytes\n" length;