Hi, On Wed, Jul 15, 2009 at 11:46, James B. Byrne<byrnejb at harte-lyne.ca> wrote: > I have a remote CentOS-5.3 installation that shares traffic with > another enterprise. I want to record and measure the actual network > traffic that comes into and goes out of that host's net i/f on a > monthly basis for billing verification purposes. Does CentOS have a > software package to accomplish this? Have a look at "netacct-mysql": http://sourceforge.net/projects/netacct-mysql/ It uses pcap which puts your network card in promiscuous mode and send all packets to the running daemon, which might be a little heavyweight on the resources if your server uses a lot of network, but it appears to be very flexible in terms of being able to split accounting for different traffic going through the server. If you want something simpler than that, you may: 1) Use "ifconfig" and save the amount of bytes received/transmitted, then do that again some time from now and subtract the difference to know how much you sent in that period. A simple script should be able to do that. Beware that that counter may wrap though. Also, you might lose the information if you reboot the server or restart the network. 2) Use "iptables" to set specific rules for what you want to account. You don't have to use "allow" or "reject" or "drop", just write the filter you want. Then use "iptables -v -L" which will show you the number of packets and bytes that went through that rule. You can then use "iptables -Z" to reset the counters for a new period. HTH, Filipe