We have a number of Linux servers for which I would like to capture netflow data to be processed by a netflow analyzer. I've been spoiled by the ease in which Mikrotik routers allow netflow data generation, but I haven't managed to find an opensource tool that is able to generate netflow data for multiple interfaces on a Linux system.
I have come across fprobe but it seems quite buggy. Admittedly I haven't spent much time with it yet since I'd also like to evaluate some other possibilities. The other tool I've seen mentioned is nprobe, which appears to be GPL, but is not available as a free download since it is only offered for a fee.
The servers on which I plan to generate netflow data are all Gentoo systems, but this shouldn't really make any difference. At most it means I would have to manually compile a tool from source.
Summary: I'm looking for an opensource netflow generator that will work on Linux and allows capturing flows for multiple interfaces.