Dual-stack BIND resolver behaviour

[lst_hoe02 at kwsoft.de]

Zitat von Anand Buddhdev <anandb at ripe.net>:

> On 16/05/2011 14:11, Dennis Perisa wrote:
>
>> Hi folks,
>>
>> We are looking to dual-stack our 9.7.3 DNS resolvers and I had a
>> question about BIND's behaviour in a dual-stack configuration.
>>
>> Assuming the resolver's cache is empty, will a query that arrives on
>> an IPv6 socket always result in an outgoing query to a root server's
>> IPv6 address? I have the same question for IPv4 queries.
>
> Hi Dennis,
>
> There's no relation between incoming recursive queries, and the outgoing
> queries BIND makes to look for answers.
>
> Whether BIND contacts the IPv4 or IPv6 address of a server (including
> the root servers) depends on the latency to that server.

Does the latency apply per IP or per Hostname? If per Hostname the  
IPv6 address will be prefered in case the root servers are reachable  
by both IPv4 and IPv6, no? Also first connection will be tried with  
IPv6 on most OS, no?

Regards

Andreas