http://www.perlmonks.org?node_id=398008

tstock has asked for the wisdom of the Perl Monks concerning the following question:

weekend monks...

I have a list of IP addresses in dot decimal format, a class A RFC 1918 internal addresses (10.0.0.0/8). I would like to scan these IP's for a service, but instead of doing it sequentially (10.0.0.1, 10.0.0.2, ...) I would like to intermix different class C's as much as possible. What I first tried did not work:
my @list = ('10.1.1.1', '10.1.1.2', '10.2.2.1', '10.2.2.2'); @list = sort intermix @list; sub intermix { return ( substr( $a, 0, rindex($a, '.')) eq substr( $b, 0, rindex($b, '.')) ) ? 1 : 0; }
Randomizing the list would be one way sort of around the sequential problem, but not as neat as what I was looking for. The reason behind the requirement is to avoid hitting limits and easy the load on individual routers/switches for each segment. Any nice perl idioms to solve this problem?

Tiago