[jfr]

Note: in your case, customer means ISP.

From what I remember, the instructions were that ISPs receive no less than /32, which should provide end-users either /48 or /56. End users use the remaining 8-16 bits to partition their networks in /64 subnets. /64 is the minimum routeable prefix, and is the prefix used for automatic configuration.

Linode offering /128 for free and /64 at a cost is ridiculous. Users will have problems to forward since that would require breaking the /64 into smaller networks (to have at least one distinct subnet at each end of the tunnel), which is not possible for radvd.