Re: I-D Action: draft-ietf-6man-rfc6434-bis-01.txt

[Nick Hilliard <[e-mail]>]

Lorenzo Colitti wrote:
> I see that the document still says:
> 
> There will be a wide range of IPv6 deployment models and differences
> in address assignment requirements, some of which may require DHCPv6
> for stateful address assignment.  Consequently, all hosts SHOULD
> implement address configuration via DHCPv6.
> 
> We should abandon this documentation, for two reasons.
> 
> First, networks that require DHCPv6 assignment are explicitly NOT 
> RECOMMENDED by current IETF best practices. Specifically, RFC 7934 
> section 8 says "it is RECOMMENDED that the network give the host the 
> ability to use new addresses without requiring explicit requests". A 
> DHCPv6-only network cannot meet this recommendation, because on a 
> DHCPv6-only network, all addresses acquisition requires an explicit 
> request to the network.
> 
> Second, the draft says "Where devices are likely to be carried by
> users and attached to multiple visisted networks, DHCPv6 client
> anonymity profiles SHOULD be supported as described in [RFC7844]".

neither of these suggestions form anything even close to an adequate
basis to drop the recommendation for dhcpv6.

The self-selection addressing model does not suit the deployment
requirements for many types of ipv6 networks, including enterprise,
provider hosting, terrestrial access networks (e.g. docsis / gpon /
ipoe) and others.  If the recommendation for dhcpv6 is dropped, then
there is no recommended ietf model for operator-assigned addressing, and
this would leave a glaring hole in the ipv6 host specification.

Just because SLAAC works for many types of ipv6 deployments, that
doesn't make it a suitable model for every situation.

Nick