This is a good catch!
I agree with your rationale, SHOULD is then intended wording, I need to
update section 5.5 accordingly.
- Alain.
On 2/5/10 2:29 PM, "Paul Selkirk" <[email protected]> wrote:
> I like the new organization of the document, and I generally support
> its adoption. It could use a bit of proofreading and word-smithing,
> but I have only one substantive objection.
>
> Section 5.5 continues to say "the B4 element MUST implement a DNS
> proxy". This is directly at odds with the new more relaxed (and more
> complete) language in section 4.2: "it SHOULD operate a DNS proxy to
> accept DNS IPv4 requests from home hosts and send them using IPv6 to
> the service provider DNS servers".
>
> I fully understand the reasons for operating a DNS proxy in the HGW in
> general, and in the B4 HGW in particular. However, there are multiple
> alternative DNS scenarios, none of which affect the operation of the
> DS-Lite protocol:
>
> 1) The HGW could operate a proxy, using a statically-configured IPv4
> resolver address (a third-party resolver, or even a resolver in the
> provider's network, learned through out of band means).
>
> 2) The HGW could not operate a proxy, but pass along a statically-
> configured IPv4 resolver address (as above) to its DHCPv4 clients in
> the home network.
>
> 3) The HGW could operate its own recursive resolver, either over IPv4
> transport or IPv6 transport.
>
> 4) Regardless of what the HGW does, a client in the home network could
> be statically configured to use a third-party resolver, or to operate
> its own recursive resolver.
>
> In all these cases, the DNS queries and responses would be tunneled
> through the AFTR like any other ds-lite traffic. As such, it places a
> marginally higher load on the AFTR (something operators might want to
> avoid), and in most cases requires static configuration (something
> else operators might want to avoid), but it is perfectly acceptable
> from a protocol point of view.
>
> This is a long-winded way of saying that I strongly feel that the MUST
> in section 5.5 needs to be changed to a SHOULD.
>
> Proofreading edits to follow shortly...
>
> paul
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