I need to know how much data are transmitted on my ppp0 network or eth0 Internet links? How do I set IP accounting by address such as 126.96.36.199 and 188.8.131.52? How do I set IP accounting per Apache virtual domain? How do I set accounting by service port (http, smtp) and protocol (tcp, udp, icmp)? How do I record how much traffic each of the clients computer is using?