If you are using Cisco 6500 switches you an use Private VLANS. They do exactly what you want without wasting IP addresses. Jeremy Brandt Infrastructure Architect Scient -----Original Message----- From: David M. Ramsey [mailto:dmr@webserve.net] Sent: Wednesday, July 26, 2000 9:54 AM To: nanog@merit.edu Subject: bw usage? Folks, I'm interested in learning which tools other people are using to measure bandwidth usage for co-located client machines on Ethernet switches. For now I've cobbled together some crude software to regularly read SNMP port byte in/out counters from our switches, stashing the deltas in a DB for later reporting/analysis. I'm concerned that the data is misleading, though, in that it will include LAN broadcast traffic. Also, customers end up paying for other bandwidth that they did not want or induce, like network scans, etc. (tough luck?). We've considered implementing unique customer VLANS to separate customer broadcast domains, but it seems like that'd be a pain, would eat up IP addresses, and possibly tax our routers with all of the ISL/VLAN stuff? Thanks in advance for any help/hints/pointers/advice you can offer. Regards, --dmr David Ramsey Charlotte, NC