On 8/Sep/15 21:31, Owen DeLong wrote:
If the ISPs equipment supports IPv6 on shared VLANs with DHCP snooping and other security, you can implement it with a single /64 giving each router a unique address within that segment, but it’s not really ideal. This was mainly done in IPv4 to conserve addresses. Separate point to point VLANs are a cleaner solution and since there are enough addresses in IPv6 to do this, that is how most providers implement. I prefer using /64s (or at least assigning /64s) to these VLANs, but there are those who argue for /127, some equipment is broken and requires a /126, and yet others argue for other nonsensical prefixes.
With Private VLAN's, one could share a single /64 per VLAN without providing Layer 2 reachability between customers on the broadcast domain. However, agree that this is a non-issue for IPv6, so a cleaner method is a lot better. Mark.