RE: I-D Action:draft-ietf-v6ops-ipv6-cpe-router-03.txt

["STARK, BARBARA H (ATTLABS)" <bs7652@att.com>]

> There might be some value in stating that it is likely that an ISP
will
> delegate a prefix that not only meets this minimum requirement but
also
> allows for a number of additional subnets downstream of the CPE, with
> the delegated prefix size likely significantly larger, possibly a /48
> or /56. IOW, stating that the delegated prefix will likely be larger
> than what is requested (not that it is probably likely, ...

The service provider will most likely completely ignore what size prefix
the CE router is requesting and will provide a prefix sized according to
service provider policy. But the CE router should go ahead and ask, just
in case the service provider does care.

> ... but I could see
> a CPE vendor adding in a check to see if the delegated prefix size was
> equal to that requested, and if it didn't, not using it).

This check would be a very Bad Idea for a CE router. Note that CE
routers, by definition, are intended for use in mass market deployments,
by people who don't understand and don't want to understand routing
protocols. They need to be able to just work, no matter what service
provider network they are connected to. And since service providers are
likely to ignore the prefix size request...

Barbara