netstat -ntu | perl -nae 'next unless $F[0] =~ /tcp|udp/;
    $seen{$F[4]}++
} {
    @keys = sort { $seen{$b} <=> $seen{$a} } keys %seen;
    printf "% " . (1 + length($seen{$keys[0]})) . "d %s\n",
           $seen{$_}, $_
        for @keys
'