Merge and de-dupe overlapping or adjacent IP ranges.
$ ./cidrmerge -?
Usage: ./cidrmerge < cidr_list [cidr_list...] > output
$
$ cat test
123.10.0.0/16
123.10.125.0/24
123.11.12.0/24
123.10.121.16
123.10.125.0/24
123.11.12.221/32
$
$ ./cidrmerge < test
123.10.0.0/16
123.11.12.0/24
$