I've been googling for hours -- Under Linux I want to know the cumulative bytes sent and received by user or by process over all ip protocols. The best I've found in my searches is that it's possible to use iptables to mark packets for a user, for example: iptables -t mangle -A OUTPUT -p tcp -m owner --uid-owner test -j MARK --set-mark 1 It appears that "tc" can then shape traffic with that but I just want the statistic -- I don't want to shape the traffic. I want something like: "user U has transmitted used XMB since time Y". I can't figure out how to get statistics from these marked packets. Also, I've looked at nethogs but they seem to be measuring the instantaneous flow and I need cumulative counts. Anyone have ideas?