I have a big network with lots of users and lots of apps ... and of cours with user complaints about apps working slow simetimes etc etc. Is there a way to monitor IP traffic and to analyse apps response times in real time, can I use netflow for that or some other product?
Netflow will show you total bandwidth and times of usages, but will not break it down by individual session, at least in any way to determine response time or something usable. It can tell you individual sessions and how much data was sent. All in all I would get MRTG or netflow to help tell you what your WAN usage is, particularly since the WAN is probably your lowest common denominator. If its all local traffic, and/or the WAN looks fine, there are some great tools out there that can troubleshoot response times, but none are free or cheap. One that comes to mind that I have used extensively in a past life is OPNet. If you dont have budget, you are probably stuck with Ethereal and the typical sniffers for log analysis.