Now we test nameserver IPv6 addresses as well. When fpdns is given

a hostname to probe, it will test both its IPv4 and IPv6 addresses
if the name has both A and AAAA records.  Also true for the -D option.

For most dual-stack name servers, this probably means we test it
twice.  However, sometimes the two addresses will be on different
servers or at least different processes, so the fingerprint might be
different.

apps/fpdns

@@ -128,21 +128,27 @@ sub dnslookup {
     return $arg if ($arg =~ $IPv4RE);
     return $arg if ($arg =~ $IPv6RE);
 
-    my $resolver =
-      Net::DNS::Resolver->new(usevc => $opt{T});
+    my $resolver = Net::DNS::Resolver->new(usevc => $opt{T});
     $resolver->srcaddr($opt{Q}) if $opt{Q};
     if ($opt{D}) {
         my $query = $resolver->send($arg, "NS");
         if ($query) {
             for my $rr ($query->answer) {
-                my $query_address = $resolver->send($rr->rdatastr, "A")
-                  if $rr->type eq "NS";
+                next unless $rr->type eq "NS";
+                my $query_address = $resolver->send($rr->rdatastr, "A");
                 if ($query_address) {
                     for my $address_rr ($query_address->answer) {
                         push @addresses, $address_rr->address
                           if $address_rr->type eq "A";
                     }
                 }
+                $query_address = $resolver->send($rr->rdatastr, "AAAA");
+                if ($query_address) {
+                    for my $address_rr ($query_address->answer) {
+                        push @addresses, $address_rr->address
+                          if $address_rr->type eq "AAAA";
+                    }
+                }
             }
         }
     } else {
@@ -152,6 +158,12 @@ sub dnslookup {
                 push @addresses, $rr->address if $rr->type eq "A";
             }
         }
+        $query = $resolver->send($arg, "AAAA");
+        if ($query) {
+            for my $rr ($query->answer) {
+                push @addresses, $rr->address if $rr->type eq "AAAA";
+            }
+        }
     }
 
     return @addresses;