Thanks again for the excellent response, and for the history lesson on why multicast was chosen over broadcast for NDP. I've done tons of work in private vlans

Thanks again for the excellent response, and for the history lesson on why multicast was chosen over broadcast for NDP. I've done tons of work in private vlans over the years. I was part of a months long effort to find and document bugs in private vlans at a vendor, where my primary focus was to find and document bugs only in private vlans. Residential ISPs love private vlans because it prevents different customers from seeing each other's broadcast traffic. DHCP Snooping to prevent things like ARP spoofing, in combination with private vlans to limit broadcast traffic will mostly lock things down pretty well. It's funny you should provide a link to a resource from the Deploy360 Programme. I just finished doing a stint with the Deploy360 Programme as a writer working on, among other things, IPv6 resources. My real name is Andrew McConachie.