Hi all, Imagine you have a number of GE and 10GE interfaces spread across multiple MX-class Juniper routers, and for each interface you want to maintain an accurate count of bytes sent, categorised by destination address. There is no layer-2 aggregation going on beyond the router, so no opportunity to create span ports on which to measure over on the side. Using optical splitters on each and every router interface and listening on the side using dedicated sniffers is an option, although it means tangles of fibre and potentially lots of sniffer boxes with lots of interfaces. I don't necessarily need a free or tremendously cheap solution, although it's always nice not to have to spend money. What are better approaches? Off-list would be fine if people have experience of this kind of thing; I can summarise if there is interest. Joe