* Augie Schwer wrote: > On Mon, May 17, 2010 at 4:04 PM, Nathan Gibbs <nat...@cmpublishers.com> wrote: >> * Augie Schwer wrote: >>> so running this monitor on an IPv4 only host, may give you some false >>> negatives. >> So if I query the IPv6 only NS from an IPv4 only host we get an error, >> although nothing is wrong. Do I got that right? > > Yes, Net::DNS::Resolver will behave as if you gave it an empty string > for the name server to query. >
All Righty.
>> Is there a TLD that has an IPv6 only NS for testing purposes?
>> I tested the monitor on .com .net .org and .info, so they don't have IPv6
>> only
>> NS's.
>
> The .us TLD has one of its six name servers that only has an IPv6 address.
OK, Thanks.
>
>> I've already done a bit of code cleanup, and was planning another release
>> soon, so it would be great if I could get this issue fixed.
>
> You'll want to loop through your list of TLD name servers and remove
> ones from the list that don't have an "A" record:
>
> my $res = Net::DNS::Resolver->new;
> my $que = $res->query($tldnsname,'A');
> if ( $que )
When there is no A record if ( !$que ) is always true.
So I never had to actually check for the A record.
Maybe that is because my system is IPv4 only.
I know enough about Net::DNS::Resolver to be dangerous, as I've already
demonstrated.
:-)
> {
> # leave loop after we found one good one.
> my @answer = $que->answer;
> last if $answer[0]->type eq 'A';
> }
>
> I know that's out of context, but you get the idea.
>
> The other thing to consider is making this all optional -- a IPv6
> enabled mon host operator may not want you to force IPv4 on them.
Correct. The new version which just went up has a -4 option to enable the
check. Otherwise it acts like the previous version and tries all the TLD NS's.
Thanks for your help.
--
Sincerely,
Nathan Gibbs
Systems Administrator
Christ Media
http://www.cmpublishers.com
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