Re: [v6ops] Fwd: New Version Notification for draft-hilliard-v6ops-host-addr-update-00.txt

[Mark Smith <[e-mail]>]

Hi,

I don't remember it being a mistake.

The fundamental intention and theme of the BCP is to ensure that hosts
can have enough addresses for whatever they and their applications
require, to ensure that lack of addresses doesn't become a constraint
hosts and applications have to work around. An on-demand, permission
based model for individual addresses doesn't prevent that constraint.

The alternative is continuing to treat addresses as though they are a
scarce resource and therefore assignment needs to be controlled at an
individual address level.

Fundamentally, we don't want hosts and application developers to have
to ask for permission from the network to innovate, nor have the
network impose artificial constraints on innovation. Artificial
address scarcity is following the traditional telephone network
scarcity model. (See David Isenberg's "Rise of the Stupid Network")


"The IPv6 self-selection addressing model does not necessarily suit
   the deployment requirements for many types of ipv6 networks,
   including enterprise, provider hosting, and various access network
   protocols (e.g.  docsis / gpon / ipoe); "

What are the specific deployment requirements?

If it is the common "address use auditing for security purposes", that
doesn't survive analysis. You can't force a malicious client to use
DHCPv6 for its addressing.

A malicious client can use statically configured addresses from within
one of the link prefixes and the DHCPv6 server won't have any record
of it.

A set of malicious clients can use link-local addresses for traffic
between themselves or bring up a new prefix on the link shared between
themselves via static configuration and the DHCPv6 server won't have
any record of it.

The RFC mentions ND cache contents recording for auditing purposes,
which is going to be much more effective, because it isn't dependent
on the address configuration method (i.e., currently stateful DHCPv6,
SLAAC, static configuration, and would accommodate any future ones if
they come into being.)

Regards,
Mark.