Re: [v6ops] Fwd: New Version Notification for draft-collink-v6ops-ent64pd-01.txt

[Alexandre Petrescu <[e-mail]>]

Le 20/12/2022 à 08:14, Vasilenko Eduard a écrit :
> * A /64 provides "infinite" addresses.
> 
> /96 is infinite too (for the host)
> 
> * In practice, /64 is the only prefix length that supports SLAAC.
> 
> Not a problem. The SLAAC may be on the different /64

A 'different' 64?  The first different bit would situate between 64th
and 96th positions or must it be somewhere before the 64th?

Would a longest-prefix match algorithm identify the difference?

When it is said that the subnet prefix length is /64 and the
delegated prefix length is /96: are these two prefixes precisely equal
in the first 64bits?

Alex

> 
> * SLAAC is the only address assignment mechanism required to be 
> supported by all hosts.
> 
> No problem. Hosts may support SLAAC and “/96 prefix per host” for a
> long time, even at the same time on the same link.
> 
> I do not see a reason why the new address acquisition mechanism
> should stick to the /64 prefix boundary.
> 
> Ed/
> 
> *From:*v6ops [mailto:[e-mail]] *On Behalf Of *Lorenzo
> Colitti *Sent:* Tuesday, December 20, 2022 10:00 AM *To:* Gert
> Doering <[e-mail]> *Cc:* V6 Ops List <[e-mail]>;
> [e-mail]; [e-mail] *Subject:* Re:
> [v6ops] Fwd: New Version Notification for 
> draft-collink-v6ops-ent64pd-01.txt
> 
> On Thu, Dec 15, 2022 at 11:44 PM Gert Doering <[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
> Something like a /96 per host - so "limitless amounts of host would 
> fit into a single /64" would avoid that, and still fulfill the stated
> necessity of having many many many addresses per hosts.
> 
> The reason the draft mentions /64 is:
> 
> * A /64 provides "infinite" addresses. * In practice, /64 is the only
> prefix length that supports SLAAC. * SLAAC is the only address
> assignment mechanism required to be supported by all hosts.
> 
> That means that a node that gets a /64 is guaranteed to be able to 
> extend the network indefinitely to all IPv6 nodes while maintaining 
> end-to-end connectivity to all of them. That's a major improvement
> over IPv4's current capabilities. It's true that a /64 is relatively
>  expensive in terms of address space. That said, this proposal is 
> targeted towards larger networks. Fortunately, smaller networks tend
> to be less tightly managed, and for many of those networks, directly
> using SLAAC is fine.
> 
> That said - based on past experience I fear that there is no single 
> number that will get consensus in this group. For example, I
> definitely wouldn't want to *recommend* /96, because /96 would lose
> the above advantages. So, how about we just state the facts?
> Something like:
> 
> =====
> 
> Delegating a /64 prefix to the client allows the client to provide 
> limitless addresses to IPv6 nodes connected to it (e.g., virtual 
> machines, tethered devices), because all IPv6 nodes are required to 
> support SLAAC.
> 
> =====
> 
> 
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