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 18.104.22.168 and 22.214.171.124? 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?
Q. How do I monitor my Bind 9 named (or any other dns server) server traffic / network traffic under Linux? How do I find out and view current DNS queries such as A, MX, PTR and so on in real time? How do I find out who is querying my DNS server or specific domain or specific dns client IP address?
Q. How do I set the routing metric on my network device under Fedora / RHEL / Red Hat / CentOS Linux server / workstation operating system?