use strict; use warnings; my $VAR1; $VAR1 = { '127' => { 'network' => '10.182.48.0/24', 'VLAN' => '3509' }, '32' => { 'network' => '10.182.12.0/25', 'VLAN' => '2121' }, '90' => { 'network' => '10.183.243.128/25', 'VLAN' => '3494' } }; sub custom { # $a and $b are keys my $anet = $VAR1->{$a}{network}; my $bnet = $VAR1->{$b}{network}; return $anet cmp $bnet; } my @result = sort custom keys %$VAR1;