Re: [v6ops] Fwd: New Version Notification for draft-ietf-dhc-pd-exclude-04.txt

[Lorenzo Colitti <[e-mail]>]

On Mon, Dec 19, 2011 at 23:49, jouni korhonen <[e-mail]>wrote:

> We added the applicability statement into the Introduction, which now
> states the pd-exclude is intended for deployments where CEs are on their
> own layer 2 domain. This should clear your concern on 'multicast RAs".
>

As discussed already, I have two objections to this on the grounds that it
needlessly complicates implementations.

First, I object to the text that says "The requesting router must create
sink routes for the delegated prefixes minus the excluded prefixes." This
is complex to implement properly.

I think it should say: "The requesting router must create sink routes for
the entire delegated prefix. If it is desired that the requesting router
route the excluded prefix in any other way, this MUST be configured to do
so via other means (for example, via a Router Advertisement containing a
Prefix Information Option for the excluded prefix and the on-link bit set).

Second, I think the draft should make it clear that only one prefix can be
excluded per delegated prefix, and that if the RR receives (at any time),
another OPTION_IAPREFIX option for the same prefix with different excluded
prefixes, then the RR is free to ignore the previous excluded prefix.