I Need help to choose the best solution to monitor the consumption of bandwidth, particularly who are consuming the bandwidth. With the SNMP protocol I can know the consumption of bandwidth but I can't know who are consuming. What are the alternatives?
Thanks to all
If you have a Cisco router, the most commonly used technology for monitoring who (or what) is consuming most of your bandwidth is Netflow. You can set it up easily (nice short guide here) and then export your flows into a tool for analysis and visualization. You can use the open source tool such as ntop or try a free evaluation version of something like Solarwinds' Netflow Traffic Analyzer or ManageEngines' Netflow Analyzer.
You could also look at the Network Analysis Module (NAM) which will give you this level of detail on your devices/network.
Thank you for your answers. The problem is that I would like pick this information in the L3 switches such as 3750 and not only to core switches such as 6500. I do not have 3750x. Is this possible?
If the L3 3750 switch is the gateway for your hosts, it's not very easy to capture flow-level data. Netflow is generally only supported on routers and high end switches like the Catalyst 6k. (Though there is a feature module for the newer 3750X's).
For an ad hoc look at the data, one could span a port and parse the data in a protocol analyzer. That's generally overkill for a simple look at flow patterns though. RMON probes are also possible thought they have generally fallen into disuse in recent years.
Do you really want to look at LOCAL bandwidth consumption (i.e., among ports on a LAN switch)? Folks seldom do that at any level of granularity except in troubleshooting specific problems since LAN bandwidth typically exceeds WAN by an order of magnitude or more and is generally over-provisioned. It's usually much easier to just watch, say, switch uplink utilization in the aggregate and add additional ones (or move servers around logically) if utilization becomes an issue.
Seeing the overall architecture and components of your system would allow us to give a better assessment.
Yes the 3750 is the gateway of multiple LANs that I want monitorize, and I want to know who is consuming the wan interface.
I know the 3750X already have NetFlow, even thought this functionality was added in a future IOS for 3750G but I think it is not possible.
With RMON I can know the consumption of bandwidth but I can't know who are consuming.