Re: RS sending in draft-ietf-v6ops-ipv6-cpe-router-04

[Ole Troan <ot@cisco.com>]

Philip,

[...]

this no longer appears to concern RSes... but.

> Some ISP do not assign any address to the WAN link and the DHCP-DP RFC prevents
> me from assigning a address from the prefix to that link. That annoys me to no
> end.

I don't understand what the problem with this is. the CPE draft recommends that an address is configured on an internal interface. why does it matter to which interface the address is on?

> But worse, when every ISP comes up with an arbitrary list of features (and
> requirements) it becomes almost impossible to help a random person with his
> internet connection.  Oh, you don't have a global IP address on WAN link, is
> that normal because the ISP doesn't assign one, or did something go wrong?
> Neighbor discovery doesn't work, is that normal because the ISP disabled it,
> or is something really broken. You only know if you know the details of 
> every ISP.

what arbitrary features are those?
there are 3 addressing models. SLAAC, DHCPv6 and "unnumbered".
all models use SLAAC.
ND is used. I'm not aware of anything that requires 'details of every ISP' to understand.

> But more practically speaking, how do you know the global IPv6 address of
> your customer? With SLAAC you would have to know the MAC address to even
> guess that address. Do you guess it based on the link-local address? Do you
> call the customer? What if the customers CPE uses temporary (privacy)
> addresses?

if you are an SP that requires to know the customers address, then you use DHCPv6 for address assignment.

> If you want that kind of control, why not prohibit customer from using there
> own CPEs? Limit official support to just the CPEs supplied by the ISP. There
> almost endless list of things random CPEs can do wrong.
> 
> With prefix delegation, a router is very likely to have at least one global
> address from the delegated prefix.

yes. are you arguing that this address should be well known? since there is no way you can assign that via DHCP. or are you arguing that there should be a mechanism to discover it? e.g by using the subnet-router anycast address?

cheers,
Ole