On Thu, 15 Jun 2006, Mikael Abrahamsson wrote: Some ciscos can do this as well (recent IOS). IP unnumbered and static routes towards vlan interfaces means you can put customers in their own vlan and still have them be part of a larger IP subnet spanning several vlans. Since it was Extreme that filed RFC3069 I seriously doubt Cisco will ever implement it straight up. I don't think it was Extreme that filed it, or at least they didn't write it. It was the good folks at Qwest engineering who came up with the idea, which was implemented (for some low value of implemented) by Extreme. The authors had moved on by the time the RFC was published, but they were certainly Qwesties (and probably CSN before that). I *think* the same idea was floated to Cisco at the same time; their PVLAN was offered in beta not long after Extreme moved super/sub-VLANs into public release. Unfortunately for those of us who had to actually implement said abomination, it didn't quite work as well as promised. In fact I was just trying to decide which was more painful, taking over a hosting network with 90% of their hosts in one VLAN (VLAN2, they asked for free advice when they first started to attempt to migrate), or supporting super/sub-VLANs in an operational environment. Customers hated both, but at least they saw better performance once the hosting network was broken up per-customer VLANs. Jeremiah