HI Woj,

Thanks for that. So we actually aren't too far apart. There needs to be a DMR 
(or equivalent) that has the IPv6 address of the BR.

But, this is one thing that's been confusing me since the publication of (I 
think v03), where the DMR is no longer described, or mentioned anywhere in the 
MAP base draft. However it does still exist in the MAP DHCP option draft. But 
neither of the drafts actually describes what it is and how to use it. The 
current map 05 draft only discusses the use of an IPv4 route, which I think is 
misleading – the IPv6 address of the BR is also needed (as Ole's pointed out in 
his mail).

A DMR, or something functionally equivalent is necessary, but this is not just 
an IPv4 route. It has to have the v6 address of the BR, used to build a tunnel. 
The v4 route points then to that tunnel.

So, the reason that I said it's incompatible is that the current text in the 
MAP base draft doesn't describe any way of getting the v6 address of the BR 
other than those that can be provided with a BMR and FMRs. I.e. An IPv4 default 
route with an IPv4 next hop which is in a map domain which the CPE has an FMR 
for. lw4o6, which doesn't use mapping rules cannot calculate the v6 address of 
the concentrator from a v4 next hop address.

I realise that this is not how it is meant to work (and you've confirmed that), 
but this is the only way that you could make it work given the text that is 
actually in the draft and that's what I think needs to be changed. This would 
bring the MAP/lw4o6 & unified CPE drafts back in line…

… then we can have the discussion about what the best DHCP mechanism to 
provision the client with the v6 address of the concentrator is :-)

Cheers,
Ian


From: Wojciech Dec <[email protected]<mailto:[email protected]>>
Date: Tuesday, 9 April 2013 18:46
To: Ian Farrer <[email protected]<mailto:[email protected]>>
Cc: Suresh Krishnan 
<[email protected]<mailto:[email protected]>>, 
Softwires-wg <[email protected]<mailto:[email protected]>>, Yong Cui 
<[email protected]<mailto:[email protected]>>, Ralph Droms 
<[email protected]<mailto:[email protected]>>
Subject: Re: [Softwires] Working group last call for draft-ietf-softwire-map-05

Hi Ian,

sure. In the current MAP the BR gets configured via the DMR (as an IP address) 
- http://tools.ietf.org/html/draft-ietf-softwire-map-dhcp-01#section-4.3
That's not set in stone, but it's a reasonable way of doing things. A name 
could be another equivalent way.

Note: The working of this, incl DHCPv6, has been verified in trials also with 
the 1:1 mode and hooking up to a DS-lite AFTR, and an issue of compatibility, 
which you're voicing a concern about, hasn't come up.

Regards,
Woj.


On 9 April 2013 17:59, <[email protected]<mailto:[email protected]>> 
wrote:
Hi Woj,

To (hopefully) prevent a long, cross purpose discussion, could you describe how 
you see that the BR address should be configured for MAP 1:1? It's described as 
a possible use case in the appendix, but it only covers how to provision the 
client, not how it learns the BR.

Thanks,
Ian

From: Wojciech Dec <[email protected]<mailto:[email protected]>>
Date: Tuesday, 9 April 2013 13:09
To: Ian Farrer <[email protected]<mailto:[email protected]>>
Cc: Suresh Krishnan 
<[email protected]<mailto:[email protected]>>, 
Softwires-wg <[email protected]<mailto:[email protected]>>, Yong Cui 
<[email protected]<mailto:[email protected]>>, Ralph Droms 
<[email protected]<mailto:[email protected]>>
Subject: Re: [Softwires] Working group last call for draft-ietf-softwire-map-05

Hi Ian,

a default route appears to be by far the best way to model the reachability of 
destinations outside of the MAP domain, and actually *any* IP domain (i.e. this 
is not a MAP specific aspect).


On 5 April 2013 21:03, <[email protected]<mailto:[email protected]>> 
wrote:
Hi,

I have one comment about the current version: It is using an IPv4 default route 
as the method for sending traffic out of the MAP domain. This is likely to 
cause provisioning complexity and conflicts with two other related drafts:

1, The unified CPE draft is looking for the presence of a configured BR/AFTR v6 
address as the mechanism for whether to configure 'binding mode' (i.e. MAP 1:1 
in this case). A v4 default route isn't easily compatible with this.

Could you elaborate on what incompatibility you see?
This is a case of an implicit default route (much as is also the norm in say 
PPP connections).


2, For DHCP based provisioning, the updated OPTION_MAP (described in the 
unified CPE draft) + RFC6334 give a method for configuring basic softwire 
functionality using just a DHCPv6 server. This doesn't provide any way of 
distributing IPv4 default routes. Therefore, to provision a MAP 1:1 client, you 
would need to deploy the DHCPv4 over DHCPv6 infrastructure just for this single 
DCHPv4 option. This is, of course assuming that the DHCPv4 over DHCPv6 method 
(draft-scskf-dhc-dhcpv4-over-dhcpv6) is the agreed mechanism for v4 over v6 
provisioning.

This appears back to front. RFC6334 is naturally the DS-lite AFTR option, and 
an AFTR does not equal a BR, (nor a Lw46 gateway). I believe that that the use 
of rfc6334 is unnecessary, and the unified CPE does not need to depend on it, 
esp given that it will need additional options anyway. In short, it makes 
little sense for a unified CPE to use both rfc6334 + some new option.


I raised this point in Orlando (See Ole's comment on using RFC6334 as the DMR 
in the minutes). I think that this change would fix the two points above.

IMO The unified CPE notion needs to be fixed (and it is something I have 
commented on previously): It's not unification by dumping all the existing 
stuff together, but a) a functional rationalization (all solution share the 
same functions) and b) a unified configuration method (which likely excludes 
things like rfc6334, given its  applicability to only one solution)

Regards,
Woj.

Thanks,
Ian




-----Original Message-----
From: [email protected]<mailto:[email protected]> 
[mailto:[email protected]<mailto:[email protected]>] On 
Behalf Of Suresh Krishnan
Sent: Dienstag, 26. März 2013 05:23
To: Softwires WG
Cc: Yong Cui; Ralph Droms
Subject: [Softwires] Working group last call for draft-ietf-softwire-map-05

Hi all,
  This message starts a two week softwire working group last call on advancing 
the draft about providing Mapping of Address and Port with Encapsulation as a 
Standards Track RFC. The authors believe that this version has addressed all 
the issues raised on the document. The latest version of the draft is available 
at

http://www.ietf.org/id/draft-ietf-softwire-map-05.txt
http://tools.ietf.org/html/draft-ietf-softwire-map-05

Substantive comments and statements of support/opposition for advancing this 
document should be directed to the mailing list. Editorial suggestions can be 
sent directly to the authors. The chairs will send in their comments as well 
during the last call period. This last call will conclude on April 9, 2013.

Regards,
Suresh & Yong
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