[CentOS] inconsistent DNS results - ping vs dig vs nslookup

Thu Jun 23 10:15:58 UTC 2011
Giles Coochey <giles at coochey.net>

On Thu, June 23, 2011 12:07, John Hodrien wrote:
> On Thu, 23 Jun 2011, Giles Coochey wrote:
>
>> Yes, I'm sure it will depend on the implementation, the trailing dot was
>> somewhat an educated guess from previous ISC BIND & dig tool use. :-)
>> As for both the A and AAAA record, I think you will have that until IPv4
>> is fully deprecated by IPv6 and no longer exists, unless, of course, you
>> want to use non IPv6 aware software (or non-IPv4 aware software...
>> shudder
>> - it will happen!).
>
> I think software still could make a better stab at things now.  You're
> doing
> AAAA lookups on a system without any IPv6 interfaces.  It's not like it's
> useful information to have if it succeeds...
>

Well, if you have access to the source, you can probably modify some
constants to disable particular protocols, or there may be compile time
options already - it would be nice to disable automatically on runtime if
the host does not have a IPv6 protocol stack.

The system calls in question are:

getaddrinfo(3)
http://www.kernel.org/doc/man-pages/online/pages/man3/getaddrinfo.3.html

or in older software:

gethostbyname(3)
http://www.kernel.org/doc/man-pages/online/pages/man3/gethostbyname.3.html