iptotal is yet another IP traffic monitor. It listens to a network interface in non-promiscuous mode, and measures IP bandwidth usage. After the specified number of seconds, the average throughput is printed at total, input and output usage.
The utility can be used to measure bandwidth usage without the need for an SNMP daemon. In combination with a simple script and rrdtool it can be used to present the measured data in graphical format e.g. through a web interface.
or you also use the pomiscuous mode with high debug level which might look like this: iptotal eth1 -r 120 -d 3 -Pinput and output measures network interface throughput web interface