US Cable Support > Comcast HSI > [IPv6] Benefits of IPv6

Easy:

In my virtualized environments typically I'll be testing things such as DHCPv6, Dynamic DNS updates, and general Microsoft-related things with IPv6 moving forward.

Unfortunately, my home LAN uses SLAAC which directly conflicts with the DHCP model. Because I don't want to uproot the entire home LAN to handle my often temporary VM networks I have to use another subnet to make that happen.

This is pretty standard behavior even in IPv4. If you build a Microsoft DHCP/DNS/AD environment out you'll encounter conflicts with the broadcasts. In IPv6's case, it's conflicts with the router advertisements and host configuration.

Under current VM solutions NAT is usually used to solve this purpose. You either use the built-in NAT for the product or you'll configure a single device to act as a NAT router with 1 bridged adapter and 1 host-only adapter.

Under IPv6 you really can't/shouldn't be using NAT and should limit its usage to as little as possible as there's really no need anymore. NAT was used to help mitigate the shortage of IPv4 addresses by allowing you to use all internal IP addressing while sharing comparatively fewer publicly routable IPv4 addresses.

This requires having more than a single /64 available to you.

Keep in mind: Many things break if you go below a /64 per subnet. IPv6 is NOT designed to do something like a /80, or /96, or anything of that nature.

Maybe I'm just tired, but I'm not sure these are good examples of why you would need or would use a larger routable address space than a /64 especially on a residential account. From what you are describing, it would seem like you would want two independent networks, one real and one virtual - in VMware lingo this is a private network or host only network. If more than one virtualization host is in use, you would need to have two NICs in the host.