> 802.1q supports 4096 vlans if I'm not mistaken. What to do if there are more than > 4K customers? There are several possible solutions. We use stacked VLANs (dual tags, what Cisco calls QinQ) and a proper aggregation platform that supports thousands of interfaces specified by outer and inner VLAN. Steinar Haug, Nethelp consulting, sthaug at nethelp.no