[Softwires] MAP&4rd-U - DS routing replaced by v6-only routing in hub&spoke topology

Rémi Després <despres.remi@laposte.net> Tue, 07 February 2012 10:13 UTC

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Date: Tue, 7 Feb 2012 11:13:11 +0100
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To: Ole Troan <otroan@employees.org>, Tetsuya Murakami <tetsuya@ipinfusion.com>, Wojciech Dec <wdec@cisco.com>
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Subject: [Softwires] MAP&4rd-U - DS routing replaced by v6-only routing in hub&spoke topology
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Hello Ole, Tetsuya-san, Wojciech,

In a use case described in the 4rd-U draft (sec 5.3), an ISP replaces its dual-stack routing by IPv6-only routing.
For this, independently from the number of IPv4 prefixes it has to support, it uses only one mapping rule.
(By replacing each IPv4 route by an equivalent IPv6 route, it ensures that all customers keep their IPv4 addresses.)

For this to work, the 4rd-U draft has a bit that, in the hub&spoke case, differs between CE-to-BR and BR-to-CE directions. Thus, packets sent to a CE take different routes depending on whether sent by a CE or a BR.

I don't see how the equivalent could work with the MAP documents you edited.
Is it that such a use case is out of scope for MAP?
Or did I miss something?

Cheers,
RD