[ntp:questions] IPv6 vs IPv4 look-ups (Was: Re: http://www.ntp.org/ => a blank page?)

Martin Burnicki martin.burnicki at meinberg.de
Thu Mar 5 14:25:56 UTC 2009


Steve Kostecke wrote:
> On 2009-03-05, Martin Burnicki <martin.burnicki at meinberg.de> wrote:
> 
>> The IPv4 address is used only after the IPv6 address has timed out, even
>> though (as far as I understand it) the DNS server first returns an IPv4
>> address, then an IPv6 address:
>>
>> # host support.ntp.org
>> support.ntp.org has address 204.152.184.138
>> support.ntp.org has IPv6 address 2001:4f8:0:2::23
> 
> On my LAN I see:
> 
> $ host support.ntp.org
> support.ntp.org       A       204.152.184.138
> 
> To resolve the IPv6 address:
> 
> $ aaaa support.ntp.org
> support.ntp.org       AAAA    2001:4F8:0:2:0:0:0:23
> 
> Both 'host' and 'aaaa' are a part of the Debian host package. The
> version I have installed is:
> 
> ||/ Name         Version       Description
>
+++-============-=============-============================================
> ii  host         20000331-9    utility for querying DNS servers

Hm, I've got an Ubuntu 8.10 machine here which AFAIK is also based on Debian
but also returns both the IPv4 and IPv6 addresses by default:

# host support.ntp.org
support.ntp.org has address 204.152.184.138
support.ntp.org has IPv6 address 2001:4f8:0:2::23

Our local DNS server running bind-9.3.1 is authoritative for our internal
domain, and forwarding other requests to DNS servers on the internet.

Martin
-- 
Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont
Germany




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