I have a customer with a small network which connects to the Internet via a Billion BiPAC 7800DXL router and a metered connection - they pay per Gigabyte.
Internet data usage is rather high, and I'd like to identify the IP addresses of the device(s) that are responsible for the bulk of the Internet traffic, so that I can then investigate further on those particular devices.
The Billion router has a bandwidth graphing feature in its Web interface, so it's possible to see overall upload/download statistics in real-time. However, what I really want is a breakdown by IP address over a longer time period - say a day or two. Cisco routers apparently have a feature called NetFlow which can be used for this. Is there anything comparable on the 7800DXL? Could some kind of logging software be used on a PC, which would extract information over a couple of days from the router via SNMP? Something like that?
I know I could insert a PC with a couple of bridged network cards and a copy of Wireshark or similar to achieve this, and I could do that if I had to, but I haven't got the hardware to hand, unfortunately. If there were some way to extract this kind of info from the router, it'd be preferable!
Any ideas, please?