$net="192.168.4.";
$counter=10;
...
$ip=$net.$counter;
...
while ( $counter <= 14 ) {
        ...
        open(LOGF,">>",$logpath . $ip);
        ...
                while ( <INFILE> ) {
                        ...
                        $ip=$net.$counter;
                        ...
                        }
                }
        $counter++;
        }