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I want to use four nameserver to look up a domain's IP.
But why the code below can lookup domain's IP only using one nameserver.


#!/usr/bin/perl
use Net:NS;
@ns=('222.33.11.2','223.55.4.3','223.55.4.2','223. 55.4.7');

for($i=0;$i<4;$i++)
{
my $res = Net:NS::Resolver->new;
$res->nameservers($ns[i]);
my $query = $res->search("www.bdchina.com");

if ($query)
{
foreach my $rr ($query->answer)
{
next unless $rr->type eq "A";
print "$ns[i]---->",$rr->address, "\n";
}
}
else
{
warn "$ns[i]---->query failed: ", $res->errorstring, "\n";
}
}

eloelo <> writes:

> I want to use four nameserver to look up a domain's IP.
> But why the code below can lookup domain's IP only using one nameserver.

Add "use warnings" to your script and let Perl tell you. Many
programmers consider "use strict" to be good practice as well.

> #!/usr/bin/perl
> use Net:NS;
> @ns=('222.33.11.2','223.55.4.3','223.55.4.2','223. 55.4.7');
>
> for($i=0;$i<4;$i++)
> {
> my $res = Net:NS::Resolver->new;
> $res->nameservers($ns[i]);
> my $query = $res->search("www.bdchina.com");
>
> if ($query)
> {
> foreach my $rr ($query->answer)
> {
> next unless $rr->type eq "A";
> print "$ns[i]---->",$rr->address, "\n";
> }
> }
> else
> {
> warn "$ns[i]---->query failed: ", $res->errorstring, "\n";
> }
> }

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/