Re: [v6ops] Updating RFC 7084

[Vasilenko Eduard <[e-mail]>]

Hi Timothy,

1.       Infrastructure may supply many prefixes for many PIOs. The host should stop using not available anymore. Or else the host may lose connectivity even if the other prefix is still alive. The host may choose the wrong one at random.

2.       Even for the only prefix – the host should be informed. Because the host may have a 3GPP link to call as backup.
Ed/
From: Timothy Winters [mailto:[e-mail]]
Sent: Monday, November 21, 2022 7:34 PM
To: Vasilenko Eduard <[e-mail]>
Cc: Ole Troan <[e-mail]>; IETF v6ops WG <[e-mail]>
Subject: Re: [v6ops] Updating RFC 7084

Hi Eduard,

You won't want all the devices to lose global addresses in the home if the (WAN) DSL link went down.  They might be communicating in the home network to other devices using global addresses.  If you unaddressed them all those connections would instantly be terminated.

~Tim

On Mon, Nov 21, 2022 at 10:59 AM Vasilenko Eduard <vasilenko.eduard=[e-mail]<mailto:[e-mail]>> wrote:
It was not about routing.
DHCP-PD propagates prefixes that would be used for PIOs.
If Carrier is not available anymore, hosts should stop using these PIOs for source addresses.
But the stub router should be informed that particular prefixes should not be used anymore.
How?
Then stub router could deprecate PIO (zero preferred lifetime).
Ed/
From: Ole Troan [mailto:otroan<mailto:otroan>=[e-mail]<mailto:[e-mail]>]
Sent: Monday, November 21, 2022 6:53 PM
To: Vasilenko Eduard <[e-mail]<mailto:[e-mail]>>
Cc: Ted Lemon <[e-mail]<mailto:[e-mail]>>; IETF v6ops WG <[e-mail]<mailto:[e-mail]>>
Subject: Re: [v6ops] Updating RFC 7084

Eduard,

I think you confuse addressing with routing.

O.

On 21 Nov 2022, at 16:39, Vasilenko Eduard <vasilenko.eduard=[e-mail]<mailto:vasilenko.eduard=[e-mail]>> wrote:

Imagine that the uplink to the Carrier (DSL for example) is down.
All hosts on the site should stop using the /48 prefix received from this carrier. It should happen preferably sub-second.
How this negative information would propagate over the site? (multi-hop)
Default PIO preferred time is 1 week. Fernando has the intention to change it to 2hours – still pretty bad.
The resolution by the current ND is very bad.
Eduard
From: Ted Lemon [mailto:[e-mail]]
Sent: Monday, November 21, 2022 6:30 PM
To: Vasilenko Eduard <[e-mail]<mailto:[e-mail]>>
Cc: IETF v6ops WG <[e-mail]<mailto:[e-mail]>>
Subject: Re: [v6ops] Updating RFC 7084

The DHCPv6 server could send a notification to the DHCPv6 client if we are concerned about this. But it’s not clear to me that we should be. If you think we should be, you need to actually make a case for that, not just assert that it’s so.

Op ma 21 nov. 2022 om 08:52 schreef Vasilenko Eduard <vasilenko.eduard=[e-mail]<mailto:[e-mail]>>
Hi all,

I do not understand how DHCP-PD may be used for prefix distribution inside the site.
Because uplink could go down.
Should be some signaling to all routers on site that the prefix is not available anymore (and should be deprecated on all links).
But DHCP is stateless in principle.
This "flush renumbering problem" would be pretty difficult to fix.
It would kill MHMP completely.

Eduard
-----Original Message-----
From: v6ops <[e-mail]<mailto:[e-mail]>> On Behalf Of Brian E Carpenter
Sent: Friday, November 18, 2022 9:02 PM
To: Timothy Winters <[e-mail]<mailto:[e-mail]>>; IPv6 Operations <[e-mail]<mailto:[e-mail]>>
Subject: Re: [v6ops] Updating RFC 7084

On 19-Nov-22 03:47, Timothy Winters wrote:
> Hello,
>
> I've started a draft to update RFC 7084 to support prefix delegation on the LAN interfaces.  The current state of IPv6 in home networks is ISP are assigning prefixes of appropriate sizes but they currently are under utilized due to the lack of prefix delegation on LAN interfaces.
>
> This draft is an attempt to add that support to the draft.
>
> https://datatracker.ietf.org/doc/draft-winters-v6ops-cpe-lan-pd/
> <https://datatracker.ietf.org/doc/draft-winters-v6ops-cpe-lan-pd/>
>
> This is only an update to 7084 at the moment, there has been some discussion on the snac working group about leveraging this work as well.
>
> One item being discussed is this currently doesn't solve multi-homed networks.

As a historical note, we've spent a lot of time in the past on multi-homing and more or less failed (and the HOMENET approach was designed for home nets, not for enterprises where the problem is probably more important).

To summarise what I've said over on SNAC:

1. If we're going to mention PvDs in the 7084 update, I think we should also mention RFC 8028. It isn't that a CE router should necessarily support 8028, but that in a network that does implement 8028 on its subnet routers, the following part of 8028 applies:

2.2.  Expectations of Multihomed Networks

    Networking equipment needs to support source/destination routing for
    at least some of the routes in the Forwarding Information Base (FIB),
    such as default egress routes differentiated by source prefix.
    Installation of source/destination routes in the FIB might be
    accomplished using static routes, Software-Defined Networking (SDN)
    technologies, or dynamic routing protocols.

Those egress routes of course lead to CE routers.

(There is some other thinking about this topic in draft-vv-6man-nd-support-mhmp).

    Brian


>
> I welcome any feedback about the proposal.
>
> ~Tim
>
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