Thanks to everyone who shared thoughts, ideas and experience regarding monitoring bandwidth usage on Ethernet switch ports without including broadcast traffic. EVERYONE tends to agree that a separate VLAN for each co-located customer is the only professional way to do things "right". I agree, and plan to move in that direction, fast. Then I won't have to worry about broadcast traffic, either! Other recommended solutions included: - MRTG This is great (I use it elsewhere) but it doesn't directly address the issue I have of *not* including broadcast traffic - Cisco 6500 switches apparently support "Private VLANS", which don't burn up IP addresses. Sounds cool, wish I had a 6500 ;-) - AUI port -- several people pointed out that an unused AUI port on a switch will log broadcast traffic and no other; I can subtract that from traffic monitored on all other ports. Some people said that an unused VLAN1 has same behavior. - dumb hub -- by plugging in a dumb, passive Ethernet hub with nothing connected, it will receive broadcast traffic. I can then subtract that ports byte counters from others. - Cisco NetFlow / cflowd ( http://www.caida.org/tools/measurement/cflowd/ ) Seems very thorough, overkill for me right now. - RMON counting of unicast-Octets only - Extracting SNMP # multicast/broadcast packets, using average packet size and subtracting product from total byte count - HPOV + SNMPv2 Regards to all, --dmr David Ramsey Charlotte, NC