This is feature request and i don't know a better way to place it. It also covers the solution.

Nearly every day I must look after banned ips and it is hard to recognize, which ones are in my list and which ones belong to a range, because they are not sorted by numbers.

The solution would be quite simple by adding an ORDER BY snippet.

Edit the file includes/acp/acp_ban.php

Look for the sql cmd in line 155:

$sql = 'SELECT *

   FROM ' . BANLIST_TABLE . '

   WHERE (ban_end >= ' . time() . "

         OR ban_end = 0)

      AND ban_ip <> ''";

Replace it with

$sql = 'SELECT *

   FROM ' . BANLIST_TABLE . '

   WHERE (ban_end >= ' . time() . "

         OR ban_end = 0)

      AND ban_ip <> ''

   ORDER BY INET_ATON(ban_ip)";

Remarks: This will work with php versions >= 5.0