trafd is a superset of trafshow, and extends it by adding a daemon
which collects data about network connections (src, dst, protocol
and length). The resulting data can be dumped to a file for later
processing.

To use trafd, your kernel must be rebuilt with the following line
added to your kernel config file (/sys/arch/<YourArch>/conf/<YourMachine>):

pseudo-device	bpfilter	8       # Berkeley packet filter

The number after bpfilter is the number of interfaces that can be
examined simultaneously. See bpf(4) for details.