Fun with maps

use strict;
use warnings;
use 5.010;
use Data::Dumper;

# ip => port => count
my $d = {
          '1.2.3.4' => {
                              '427029' => 41,
                              '420617' => 42,
                       }, 
          '1.2.3.5' => {
                              '551509' => 51,
                              '517427' => 52,
                       }, 
          '1.2.3.6' => { 
                              '671500' => 61,
                              '622331' => 62,
                       }, 
};
my $ip;
say for sort map {
   $ip = $_;map {
     sprintf "%04d connections %s -> %s", $d->{$ip}->{$_}, $ip, $_ 
   } keys %{$d->{$ip}} 
} keys %$d;
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Cheers,
R.