Re: NAT-PT: DNS ALG question

[Senthil Sivakumar <ssenthil@cisco.com>]

At 10:59 AM 11/19/2003 +0800, CTO WEI Renxiang wrote:

> Hi,
>
> I wanted to know what would be the correct behavior for the
> following
> scenario. 
>
> Suppose a mix(include both IPv4 and IPv6 host) network with
> a NAT-PT and DNS-ALG deployed 
> on the border. An
> outside IPv4 client host sends a A query, thru NAT-PT, to a DNS 
> server in this mix network. NAT-PT RFC says that a A need to be translated into AAAA, 
> but if the host in this mix network been queried is an IPv4-only host, the result will not be correct. 
> The RFC really doesn't say anything like that. 

These two v4 devices should have had some means of communicating before NAT-PT, which is
probably NAT. And I would assume that they continue to talk to each other using NAT. If
you say that the NAT and NAT-PT are running in the same box, then it would become a coexistence
and/or implementation issue and you won't find those issues in NAT-PT RFC. 

> Should DNS-ALG need to query the DNS server in this mix network before it translates the A to AAAA?
>
> Thanks
> Renxiang