On 7/19/11 1:10 PM, Ahmed Abu-Abed wrote:
Currently the smallest network of physical devices (a home user's subnet) gets the largest block of addresses (/64 in size) from the LIR. There is a logic issue here.
Thus we get the need for larger LIR IPv6 allocations. And dependencies on /64 subnets go beyond SLAAC and ND.
If/when RIPE has a say on what happens beyond 2000::/3, where /64 subnets are required, then we can come up with ideas on smallest subnet size. Hardware should be sophisticated enough by then to handle such practical needs in case bit alignment is an issue.
Please, stop here. Do not go any further. We are taking all possible measures to discourage development and deployment of devices and mechanisms that would enable use of prefixes shorter than /64 in one link-layer network. For example with initial /32 you could deploy 6RD in one 6RD domain, but would give to user only one /64. In this case sooner or later the need will emerge to develop something that magically enables you to split /64 to more subnets and actually use that. This is all about adding another layer of complexity and indirection to already messy world. That's one of reasons we are discouraging assignments of /64 to a user. Use /56 or /48 instead and avoid the pain later. Cheers, Jan