Re: [v6ops] draft-smith-v6ops-local-only-addressing

[Fernando Gont <[e-mail]>]

Mark,

Here are my comments:

* Meta:
I find it valuable to explore different ways of leveraging IPv6
addressing capabilities. In a way, it's a shame that given the lack of
advice we have in this area, hosts/application are doing, at best,
sub-optimal use of it.


* Things that I think that are missing:

  + It would seem to me that your document should somehow that CPEs and
DHCPv6 servers advirtise/lease ULAs, in addition of global
addresses/prefixes? -- otherwise, it will be more unlikely that these
devices get to configure ULAs

  + You might clarify that ULAs *might* be reachable from other networks
if not properly filtered at the border.

  + IIRC this one was discussed at the last IETF meeting: how would e.g.
automatic updates work?

  + The document should analyze why "only local" vs. "configure all, but
do not allow incomming comunications"



* Specific comments:

>    By default, a Local Only Address device MUST only configure Link-
>    Local and non-global IPv6 addresses, currently Unique Local Addresses
>    [RFC4193], on its network interfaces.

You might want to clarify the terminology esp in the context of RFC8190.



>    By default, if there are no ULA prefix PIOs in the received RAs, or
>    no ULA prefix PIOs with the A flag set, the Local Only Addresses
>    device MUST only configure IPv6 Link-Local addresses on its network
>    interface.

The text might be misleading/mis-interpreted: normally, at point you
process RAs with PIOs, you have already configured link-locals.  (the
text might be interpreted like you configure them when there are no ULA
prefixes with the A bit set).



>    By default, if there are ULA prefix PIOs that do not have the A flag
>    set, they MUST be processed per standard RA PIO processing for other
>    flags.  For example, a PIO for a ULA prefix, with the A flag unset,
>    and the L or on-link flag set, is still processed, and is asserting
>    that the specified ULA prefix is on-link.

I'd omit this para -- you are not changing the current state of affairs.



>    If the Configure All IPv6 Addresses configuration switch is enabled,
>    then the Local Only Addresses device MUST process all IPv6 RA PIOs
>    received for SLAAC address configuration, per [RFC4862], from that
>    point in time onwards.

Same here. So I'd rephrase as ""If... normal processing of RAs takes
place, honoring all prefixes" or the like.


> 
>    By default, a Local Address Only device MUST NOT accept any upper
>    layer connections from any global IPv6 addresses.


s/upper layer/transport layer/?


>    An application may attempt to overcome this global IPv6 address
>    constraint by constructing packets itself that contain a global IPv6
>    address source address.  T

Not sure what this means.... the app crafting IPv6 pckets?



Thanks!

Cheers,
Fernando




-- 
Fernando Gont
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