Re: [Anima] Whether IPv6 only for ACP? //RE: I-D Action: draft-behringer-anima-autonomic-addressing-01.txt

On 25/06/2015 14:06, Duzongpeng wrote:
> Hi, Michael Richardson:
> 
> 	I agree with your option. Perhaps ACP is not needed to be IPv6 only.

However, IPv6 has an enormous advantage in a cold start with all devices
assumed in factory condition. Every IPv6 stack will acquire a valid link-local
address even if no other device (such as a router or DHCP server) is configured
and there is no Intent in place. That is what we need for a true AN.

> 
> 	Of course, an IPv6 only autonomic control plane is ok for all the services in autonomic network, and the solution has the advantage of simplicity as mentioned by Michael Behringer.
> 
> 	However, the network operator may be more familiar with the IPv4-base management.

I'm sorry but such operators are quickly becoming dinosaurs. Looking at the
current growth rate of IPv6, and knowing that it will take several years
for Anima work to be complete, I think those operators will be in serious
trouble.

> 	In the beginning of the ACP deployment, the network operator may not be very confident about the decisions made by the autonomic network. Some kinds of monitoring jobs may be desired by the network operators. At this time, the operator may want to see some IPv4 addresses. 

Their traditional NMS could still be IPv4, and they could still see IPv4 information
through an IPv6 ACP.

> So, perhaps we need to provide IPv4-based ACP as an option for these parts of operators. Otherwise, we can only answer them "sorry, we only support IPv6 here".

No, the answer is "IPv6 will be deployed automatically with no work by you, but
old IPv4 services will not be interrupted."

Actually we should think about an "IPv4 management" use case for AN, running
over an IPv6 ACP.

Best regards,
   Brian

> 
> 	As IPv4 has been widely deployed, perhaps an IPv4-based autonomic network will be accepted by more network managers at the beginning.
> 
> 	Indeed, at this time, an IPv4-based ACP is not as mature as the IPv6 one. Thus, perhaps some work needs to be done at this direction. For example, as you mentioned, how can we get an address instead of the ULA in IPv6.
> 
> Best regards
> Zongpeng Du
> 
> -----Original Message-----
> From: Anima [mailto:anima-bounces@ietf.org] On Behalf Of Michael Richardson
> Sent: Thursday, June 25, 2015 1:12 AM
> To: Michael Behringer (mbehring)
> Cc: Anima WG
> Subject: Re: [Anima] I-D Action: draft-behringer-anima-autonomic-addressing-01.txt
> 
> 
> Michael Behringer (mbehring) <mbehring@cisco.com> wrote:
>     >> > IPv6 only: Autonomic processes should use exclusively IPv6, for
>     >> > simplicity reasons.
>     >>
>     >> I agree with this as long as it's an RFC 2119 SHOULD, i.e. IPv4 could be used in
>     >> extraordinary circumstances. The GDNP design is fundamentally IP-version
>     >> independent.
> 
>     > Yes, as long as it's really "extraordinary" ;-)   That 2119 says
>     > "SHOULD" means like you need a really good reason to not do it. What
>     > would such a good reason be? Just saying, in our implementation we
>     > often get the requirement "we want IPv4", and when you dig, the reason
>     > is that they don't want to deploy IPv6, and that's the only
>     > reason. Slippery slope...
> 
> a) to respond to the immediate "we want IPv4" --- I'd just tell the customer
>    that it uses a custom link layer protocol that uses an ethernet type
>    different than 0x0800... just like CDP does :-)
>    (I don't think you need to "deploy" IPv6 to have an ACP...)
> 
> b) the only thing I care about is that nobody is allowed to say, "but
>    mechanism XYZ does not exist in IPv4".  That's all.  I don't know if
>    we will need IPv6-only things, but maybe.
> 
> ...
> 
>     >> Use-ULA: For these overlay addresses of autonomic nodes, we use Unique
>     >> Local Addresses (ULA), as specified in [RFC4193].  An alternative
>     >> scheme was discussed, using assigned ULA addressing.  The consensus
>     >> was to use standard ULA, because it was deemed to be sufficient.
> 
> It might be that ULA is an IPv6-only feature.
> I don't consider 10/8 to be the same, as it is not statistically unique inside the AS.
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works  -= IPv6 IoT consulting =-
> 
> 
> 
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