This was covered here a while back. Here's one way that uses a cache to cut down on the number of packs required.

my %cache = ();
my @sorted = sort {
        $cache{$a} ||= pack('C4' => $a =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/);
        $cache{$b} ||= pack('C4' => $b =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/);
        $cache{$a} cmp $cache{$b};
} @unsorted;