Specifically answering your question, MRTG is a great network management tool, however it will only give you the amount/percentage of bandwidth utilization for a specific SNMP based IP address and/or interface. It will not give you protocol specific utilization. In order to accomplish this you need additional management tools such as a Network Associates Sniffer or a network management program (HP Openview, Ciscoworks 2000, Netsys) used in conjunction with an RMON II probe. A Sniffer will allow you to capture data off the wire from device to device, device to subnet, device to protocol, etc,. Assuming your devices are RMON complient, without a probe (hardware or software) you'll only get the first four groups: (statistics, history, alarms and events), normally referred to as RMON I or RMON lite. The data you are requesting is in the last five groups, specifically the Hosts Top N or Traffic Matrix. This can only be retreived with an RMON II probe. In my opinion, the best way to accomplish your goal is with a Network Associates Sniffer. It's flexable, can be used to retreive a tremendous amount of information, great for baselining and troubleshooting, and is a heck of a lot cheaper than Cisco's network management software and the overpriced RMON probe. Hope this helps.
Steve Tate
MCSE, MCT, NNCSS, CCNP, CCDP
