Subject: [v6ops] draft-ietf-v6ops-unique-ipv6-prefix-per-host-01

From: "Bernie Volz (volz)" <[email-masked]>
Date: Sat, 9 Jul 2016 15:27:16 +0000

Hi:

Did you perhaps miss some edits late in the document (Section 5):

   An operational consideration when using IPv6 address assignment using
   IPv6 SLAAC is that after the onboarding procedure the UE/subscriber
   will have a prefix with certain preferred and valid lifetimes.  The
   First Hop Provider Router extends these lifetimes by sending an
   unsolicited RA, the applicable MaxRtrAdvInterval on the WLAN-GW MUST
   therefore be lower than the preferred lifetime.  As a consequence of
   this process is that the First Hop Router never knows when a UE/
   subscriber stops using addresses from a prefix and additional
   procedures are required to help the First Hop Router to gain this
   information.  When using stateful DHCPv6 IA_NA for IPv6 UE/subscriber
   address assignment this uncertainty on the First Hop Router is not of
   impact due to the stateful nature of DHCPv6 IA_NA address assignment.

And I'm not really sure how the stateful nature of DHCP helps significantly with this issue. The RA's preferred/valid lifetime are really no different than DHCPv6's preferred/valid lifetimes and could easily be made the same. (While a DHCPv6 client would normally renew at ½ the preferred lifetime, that is not a hard requirement and therefore a DHCPv6 server must still assume that the address is in use until the valid-lifetime has expired.) Sure, a DHCPv6 client COULD send a Release message to give up its address, but that is rarely done in practice.

And a bit later (RFC4941):

   When employing stateless IPv6 address assignment a number of widely
   deployed operating systems will attempt to utilize RFC 4941 RFC4941
   [RFC4941] temporary 'private' addresses.  This can lead to the

And is there much benefit is including:

6.  Future work

   o  Informational draft regarding WLAN IPv6 Deployment technology
      experiences roll-out

It would perhaps be useful if you had a draft to reference, but otherwise not so much?

-          Bernie

---

From: "Van De Velde, Gunter (Nokia - BE)" <[email-masked]>
Date: Mon, 18 Jul 2016 09:23:38 +0000

Yep, good catch. I indeed missed these when doing the edit on this latest version to split out the /64 assignment per host.

Next version I’ll take this comment into account.

Many thanks,
G/

From: "Bernie Volz (volz)" <[email-masked]>
Date: Saturday 9 July 2016 at 17:27
To: "[email-masked]" <[email-masked]>
Cc: "[email-masked]" <[email-masked]>
Subject: draft-ietf-v6ops-unique-ipv6-prefix-per-host-01
Resent-From: <[email-masked]>
Resent-To: <[email-masked]>, <[email-masked]>
Resent-Date: Saturday 9 July 2016 at 17:27

Hi:

And I’m not really sure how the stateful nature of DHCP helps significantly with this issue. The RA’s preferred/valid lifetime are really no different than DHCPv6’s preferred/valid lifetimes and could easily be made the same. (While a DHCPv6 client would normally renew at ½ the preferred lifetime, that is not a hard requirement and therefore a DHCPv6 server must still assume that the address is in use until the valid-lifetime has expired.) Sure, a DHCPv6 client COULD send a Release message to give up its address, but that is rarely done in practice.

6.  Future work

-          Bernie

---

From: "Mukom Akong T." <[email-masked]>
Date: Sun, 24 Jul 2016 08:40:27 +0200

(I'm reposting this under this thread so ask to keep the conversation about
this draft in a single place. apologies for the duplicate)

Section 4 says

[snip]

The architected result of designing the RA as documented above is
   that each UE/subscriber gets its own unique /64 IPv6 prefix for which
   it can use SLAAC or any other method to select its /128 unique
   address.  In addition it will use stateless DHCPv6 to get the IPv6
   address of the DNS server, however it SHOULD NOT use stateful DHCPv6
   to receive a service provider managed IPv6 address.  If the UE/
   subscriber desires to send anything external including other UE/
   subscriber devices (assuming device to device communications is
   enabled and supported), then due to the L-bit set it SHOULD send this
   traffic to the First Hop Provider Router.

[/snip]

Question #1

Any reason for silence about the  possibility of passing DNS parameters
within the RAs as per RFC 6106?

Perhaps the statement

" In addition, it will use stateless DHCPv6 to get the IPv6 address of the
DNS server ..."

may be replaced with

"The UE depending upon its capabilities should get DNS information either
from the RA as per RFC6106 or via stateless DHCPv6"

On 18 July 2016 at 11:23, Van De Velde, Gunter (Nokia - BE) <
[email-masked]> wrote:

> Yep, good catch. I indeed missed these when doing the edit on this latest
> version to split out the /64 assignment per host.
>
>
>
> *From: *"Bernie Volz (volz)" <[email-masked]>
> *Date: *Saturday 9 July 2016 at 17:27
> *To: *"[email-masked]" <
> [email-masked]>
> *Cc: *"[email-masked]" <[email-masked]>
> *Subject: *draft-ietf-v6ops-unique-ipv6-prefix-per-host-01
> *Resent-From: *<[email-masked]>
> *Resent-To: *<[email-masked]>, <
> [email-masked]>
> *Resent-Date: *Saturday 9 July 2016 at 17:27
>
>
>
> Hi:
>
>
>
> And I’m not really sure how the stateful nature of DHCP helps
> significantly with this issue. The RA’s preferred/valid lifetime are really
> no different than DHCPv6’s preferred/valid lifetimes and could easily be
> made the same. (While a DHCPv6 client would normally renew at ½ the
> preferred lifetime, that is not a hard requirement and therefore a DHCPv6
> server must still assume that the address is in use until the
> valid-lifetime has expired.) Sure, a DHCPv6 client COULD send a Release
> message to give up its address, but that is rarely done in practice.
>
>
>
> _______________________________________________
> v6ops mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/v6ops
>
>

-- 

Mukom Akong T.

LinkedIn:Mukom <https://www.linkedin.com/in/mukom>  |  twitter:
@perfexcellent

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